Add dmd 2.075.0 support

std.algorithm.mutation copy is unable to copy a char range into a char array slice.

.editorconfig

@@ -0,0 +1,9 @@
+root = true
+
+[*]
+end_of_line = lf
+insert_final_newline = true
+charset = utf-8
+indent_style = space
+indent_size = 4
+trim_trailing_whitespace = true

.gitignore

@@ -1,11 +1,14 @@
 # Binary
 *.[oa]
+*.exe
 
 # D
 .dub
 __test__*__
 __test__*__.core
-/tanya-test-library
+/tanya-test-library*
 
 /docs/
 /docs.json
+
+/*.lst

.travis.yml

@@ -7,14 +7,32 @@ os:
 language: d
 
 d:
+  - dmd-2.075.0
+  - dmd-2.074.1
   - dmd-2.073.2
   - dmd-2.072.2
   - dmd-2.071.2
- - dmd-2.070.2
 
 env: 
   matrix:
     - ARCH=x86_64
+    - ARCH=x86
+
+addons:
+  apt:
+    packages:
+      - gcc-multilib
+
+before_script:
+  - if [ "$PS1" = '(dmd-2.075.0)' ]; then
+      export UNITTEST="unittest-cov";
+    fi
 
 script:
- - dub test --arch=$ARCH
+  - dub test -b ${UNITTEST:-unittest} --arch=$ARCH --compiler=$DC
+  - if [ "$UNITTEST" = "unittest-cov" -a "$ARCH" = "x86_64" -a "$TRAVIS_OS_NAME" = "linux" ]; then
+      dub fetch dscanner && dub run dscanner -- -Isource --styleCheck;
+    fi
+
+after_success:
+  - test "$UNITTEST" = "unittest-cov" && bash <(curl -s https://codecov.io/bash)

CODE_OF_CONDUCT.md

@@ -0,0 +1,5 @@
+# Contributor Code of Conduct
+
+This project adheres to No Code of Conduct.  We are all adults.  We accept anyone's contributions.  Nothing else matters.
+
+For more information please visit the [No Code of Conduct](https://github.com/domgetter/NCoC) homepage.

CONTRIBUTING.md

@@ -0,0 +1,92 @@
+# Contributing
+
+Tanya is a project in active development, therefore any help is appreciated. Thank you for considering contributing
+to it, feel welcome.
+These guidelines describe ways to get started.
+
+
+## Ways to get involved
+
+* **Reporting a problem**: [Report](https://issues.caraus.io/projects/tanya/issues) bugs and usage problems you
+encounter.
+* **Fixing issues**: [The bug tracker](https://issues.caraus.io/projects/tanya/issues) contains a list of issues you
+can work on.
+* **Documentation**: You can improve API documentation by correcting grammar errors, completing existing texts and
+writing new ones, or providing usage examples.
+* **Testing**: Test coverage is important for a library. Writing tests is not only helpful, but is also a great way
+to get a feel for how tanya works.
+* **Adding new features**: Tanya is a growing library. If you think some feature is missing, you can suggest
+and implement this.
+
+
+## Opening an issue
+
+If you have found a bug, an error, have some question, or suggestion, open in issue. I'll try to answer as soon
+as I can. Tanya uses an external
+[bug tracker](https://issues.caraus.io/projects/tanya/issues). You should
+[register](https://issues.caraus.io/account/register) before you can report your issue. There is also a list
+of open issues that mirror the current development process and progress. If you're looking for a challenge, just
+pick an issue you are interested in and start working on it. Fill free to comment on the issue to get more
+information.
+
+Some issues have a category assigned to them. Such issues belong mostly to a larger part of the library that is
+currently in development. The category specifies then the git branch development happens on. The remaining issues
+can be fixed directly in master.
+
+In the [roadmap](https://issues.caraus.io/projects/tanya/roadmap) you can find a list of issues that are planned
+to be fixed till a specific release. Version numbers refer to the versions in the
+[git repository](https://github.com/caraus-ecms/tanya/releases).
+
+
+## Contribution process
+
+### Creating a pull request
+
+I accept GitHub pull requests. Creating a pull request is like sending a patch with the suggested change.
+First you have to [fork](https://guides.github.com/activities/forking/) the repository. Clone your fork locally
+with `git clone` and create a new branch where you want to work, for example:
+
+```shell
+git checkout -b bugfix-x
+```
+Commit your changes to your fork:
+
+```shell
+git commit -m "Fix X"
+git push -u origin bugfix-x
+```
+
+After that if you visit your fork on GitHub, GitHub will suggest to create pull request. Just follow the steps
+described on GitHub to finish the process. See
+[Using Pull Requests](https://help.github.com/articles/about-pull-requests/) for more information.
+
+Please ensure that your fork is even with the upstream (original) repository. If not, you have to rebase your branch
+on upstream/master before submitting a pull request. See https://help.github.com/articles/syncing-a-fork/ for a
+step-by-step guide.
+
+### Fixing a bug
+
+Add an unittest that demonstrates the bug along with a short description:
+
+```d
+// Issue ###: https://issues.caraus.io/issues/###.
+private unittest
+{
+}
+```
+
+### Adding new features
+
+* Use Ddoc to document the feature.
+* Add some unittests that prevent new bugs and demonstrate how the feature is supposed to work.
+
+### Style guide
+
+Make sure your changes follow [The D Style](https://dlang.org/dstyle.html) (including
+[Additional Requirements for Phobos](https://dlang.org/dstyle.html#phobos).
+
+
+## Questions and suggestions
+
+* [Open an issue](https://issues.caraus.io/projects/tanya/issues)
+* [Send an email](mailto:info@caraus.de)

README.md

@@ -1,6 +1,8 @@
 # Tanya
 
-[![Build Status](https://travis-ci.org/caraus-ecms/tanya.svg?branch=master)](https://travis-ci.org/caraus-ecms/tanya)
+[![Build status](https://travis-ci.org/caraus-ecms/tanya.svg?branch=master)](https://travis-ci.org/caraus-ecms/tanya)
+[![Build status](https://ci.appveyor.com/api/projects/status/djkmverdfsylc7ti/branch/master?svg=true)](https://ci.appveyor.com/project/belka-ew/tanya/branch/master)
+[![codecov](https://codecov.io/gh/caraus-ecms/tanya/branch/master/graph/badge.svg)](https://codecov.io/gh/caraus-ecms/tanya)
 [![Dub version](https://img.shields.io/dub/v/tanya.svg)](https://code.dlang.org/packages/tanya)
 [![Dub downloads](https://img.shields.io/dub/dt/tanya.svg)](https://code.dlang.org/packages/tanya)
 [![License](https://img.shields.io/badge/license-MPL_2.0-blue.svg)](https://raw.githubusercontent.com/caraus-ecms/tanya/master/LICENSE)
@@ -13,54 +15,163 @@ Garbage Collector heap. Everything in the library is usable in @nogc code.
 Tanya extends Phobos functionality and provides alternative implementations for
 data structures and utilities that depend on the Garbage Collector in Phobos.
 
-* [Bug tracker](https://issues.caraus.io/projects/tanya)
+* [Bug tracker](https://issues.caraus.io/projects/tanya/issues)
 * [Documentation](https://docs.caraus.io/tanya)
+* [Contribution guidelines](CONTRIBUTING.md)
+
 
 ## Overview
 
-Tanya consists of the following packages:
+Tanya consists of the following packages and (top-level) modules:
 
 * `async`: Event loop (epoll, kqueue and IOCP).
-* `container`: Queue, Vector, Singly linked list, buffers.
+* `container`: Queue, Array, Singly and doubly linked lists, Buffers, UTF-8
+string, Hash set.
+* `format`: Formatting and conversion functions.
 * `math`: Arbitrary precision integer and a set of functions.
-* `memory`: Tools for manual memory management (allocator, reference counting,
-helper functions).
-* `network`: URL-Parsing, sockets.
+* `memory`: Tools for manual memory management (allocators, smart pointers).
+* `net`: URL-Parsing, network programming.
+* `network`: Socket implementation. `network` is currently under rework.
+After finishing the new socket implementation will land in the `net` package and
+`network` will be deprecated.
+* `os`: Platform-independent interfaces to operating system functionality.
+* `typecons`: Templates that allow to build new types based on the available
+ones.
+
+
+## Basic usage
+
+### Allocators
+
+Memory management is done with allocators. Instead of using `new` to create an
+instance of a class, an allocator is used:
+
+```d
+import tanya.memory;
+
+class A
+{
+    this(int arg)
+    {
+    }
+}
+
+A a = defaultAllocator.make!A(5);
+
+defaultAllocator.dispose(a);
+```
+
+As you can see, the user is responsible for deallocation, therefore `dispose`
+is called at the end.
+
+If you want to change the `defaultAllocator` to something different, you
+probably want to do it at the program's beginning. Or you can invoke another
+allocator directly. It is important to ensure that the object is destroyed
+using the same allocator that was used to allocate it.
+
+What if I get an allocated object from some function? The generic rule is: If
+you haven't requested the memory yourself (with `make`), you don't need to free
+it.
+
+`tanya.memory.smartref` contains smart pointers, helpers that can take care of
+a proper deallocation in some cases for you.
+
+### Exceptions
+
+Since exceptions are normal classes in D, they are allocated and dellocated the
+same as described above, but:
+
+1. The caller is **always** responsible for destroying a caught exception.
+2. Exceptions are **always** allocated and should be always allocated with the
+`defaultAllocator`.
+
+```d
+import tanya.memory;
+
+void functionThatThrows()
+{
+    throw defaultAlocator.make!Exception("An error occurred");
+}
+
+try
+{
+    functionThatThrows()
+}
+catch (Exception e)
+{
+    defaultAllocator.dispose(e);
+}
+```
+
+### Containers
+
+Arrays are commonly used in programming. D's built-in arrays often rely on the
+GC. It is inconvenient to change their size, reserve memory for future use and
+so on. Containers can help here. The following example demonstrates how
+`tanya.container.array.Array` can be used instead of `int[]`.
+
+```d
+import tanya.container.array;
+
+Array!int arr;
+
+// Reserve memory if I know that my container will contain approximately 15
+// elements.
+arr.reserve(15);
+
+arr.insertBack(5); // Add one element.
+arr.length = 10; // New elements are initialized to 0.
+
+// Iterate over the first five elements.
+foreach (el; arr[0 .. 5])
+{
+}
+
+int i = arr[7]; // Access 7th element.
+```
+
+There are more containers in the `tanya.container` package.
+
+
+## Development
 
 ### Supported compilers
 
-* dmd 2.073.2
-* dmd 2.072.2
-* dmd 2.071.2
-* dmd 2.070.2
+| dmd     |
+|:-------:|
+| 2.075.0 |
+| 2.074.1 |
+| 2.073.2 |
+| 2.072.2 |
+| 2.071.2 |
 
 ### Current status
 
-The library is currently under development, but the API is becoming gradually
-stable.
+Following modules are under development:
 
-`container`s are being extended to support ranges. Also following modules are
-coming soon:
-* UTF-8 string.
-* Hash table.
+| Feature  | Branch    | Build status                                                                                                                                                                                                                                                                                  |
+|----------|:---------:|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| BitArray | bitvector | [![bitvector](https://travis-ci.org/caraus-ecms/tanya.svg?branch=bitvector)](https://travis-ci.org/caraus-ecms/tanya) [![bitvector](https://ci.appveyor.com/api/projects/status/djkmverdfsylc7ti/branch/bitvector?svg=true)](https://ci.appveyor.com/project/belka-ew/tanya/branch/bitvector) |
+| TLS      | crypto    | [![crypto](https://travis-ci.org/caraus-ecms/tanya.svg?branch=crypto)](https://travis-ci.org/caraus-ecms/tanya) [![crypto](https://ci.appveyor.com/api/projects/status/djkmverdfsylc7ti/branch/crypto?svg=true)](https://ci.appveyor.com/project/belka-ew/tanya/branch/crypto)                |
+| File IO  | io        | [![io](https://travis-ci.org/caraus-ecms/tanya.svg?branch=io)](https://travis-ci.org/caraus-ecms/tanya) [![io](https://ci.appveyor.com/api/projects/status/djkmverdfsylc7ti/branch/io?svg=true)](https://ci.appveyor.com/project/belka-ew/tanya/branch/io)                                    |
 
-`math` package contains an arbitrary precision integer implementation that
-needs more test cases, better performance and some additional features
-(constructing from a string and an ubyte array, and converting it back).
+### Release management
 
-### Further characteristics
+3-week release cycle.
 
-* Tanya is a native D library.
+Deprecated features are removed after one release (in approximately 6 weeks after deprecating).
+
+## Further characteristics
+
+* Tanya is a native D library without any external dependencies.
 
 * Tanya is cross-platform. The development happens on a 64-bit Linux, but it
 is being tested on Windows and FreeBSD as well.
 
-* The library isn't thread-safe. Thread-safity should be added later.
+* The library isn't thread-safe yet.
 
-## Contributing
 
-Since I'm mostly busy writing new code and implementing new features I would
-appreciate, if anyone uses the library. It would help me to improve the
-codebase and fix issues.
+## Feedback
 
-Feel free to contact me if you have any questions.
+Any feedback about your experience with tanya would be greatly appreciated. Feel free to
+[contact me](mailto:info@caraus.de).

appveyor.yml

@@ -0,0 +1,78 @@
+platform: x64
+os: Visual Studio 2015
+
+environment:
+  matrix:
+    - DC: dmd
+      DVersion: 2.075.0
+      arch: x64
+    - DC: dmd
+      DVersion: 2.075.0
+      arch: x86
+    - DC: dmd
+      DVersion: 2.074.1
+      arch: x64
+    - DC: dmd
+      DVersion: 2.074.1
+      arch: x86
+    - DC: dmd
+      DVersion: 2.073.2
+      arch: x64
+    - DC: dmd
+      DVersion: 2.073.2
+      arch: x86
+    - DC: dmd
+      DVersion: 2.072.2
+      arch: x64
+    - DC: dmd
+      DVersion: 2.072.2
+      arch: x86
+    - DC: dmd
+      DVersion: 2.071.2
+      arch: x64
+    - DC: dmd
+      DVersion: 2.071.2
+      arch: x86
+
+skip_tags: true
+
+install:
+  - ps: function SetUpDCompiler
+        {
+          $env:toolchain = "msvc";
+          $version = $env:DVersion;
+          Invoke-WebRequest "http://downloads.dlang.org/releases/2.x/$($version)/dmd.$($version).windows.7z" -OutFile "c:\dmd.7z";
+          echo "finished.";
+          pushd c:\\;
+          7z x dmd.7z > $null;
+          popd;
+        }
+  - ps: SetUpDCompiler
+
+  - ps: if($env:DVersion -eq "2.071.2"){
+          Invoke-WebRequest "http://code.dlang.org/files/dub-1.2.1-windows-x86.zip" -OutFile "dub.zip";
+          7z x dub.zip -odub > $null;
+          Move-Item "dub/dub.exe" "C:\dmd2\windows\bin"
+        }
+
+before_build:
+  - ps: if($env:arch -eq "x86"){
+          $env:compilersetupargs = "x86";
+          $env:Darch = "x86";
+        }
+        elseif($env:arch -eq "x64"){
+          $env:compilersetupargs = "amd64";
+          $env:Darch = "x86_64";
+        }
+  - ps: $env:PATH += ";C:\dmd2\windows\bin;";
+  - call "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall" %compilersetupargs%
+
+build_script:
+  - echo dummy build script - dont remove me
+
+test_script:
+  - echo %Darch%
+  - echo %PATH%
+  - 'dub --version'
+  - '%DC% --version'
+  - dub test -b unittest --arch=%Darch% --compiler=%DC%

codecov.yml

@@ -0,0 +1,3 @@
+ignore:
+  - "source/tanya/async/event/iocp.d"
+  - "source/tanya/async/iocp.d"

dscanner.ini

@@ -0,0 +1,81 @@
+; Configure which static analysis checks are skip-unittest
+[analysis.config.StaticAnalysisConfig]
+; Check variable, class, struct, interface, union, and function names against t
+; he Phobos style guide
+style_check="disabled"
+; Check for array literals that cause unnecessary allocation
+enum_array_literal_check="skip-unittest"
+; Check for poor exception handling practices
+exception_check="skip-unittest"
+; Check for use of the deprecated 'delete' keyword
+delete_check="skip-unittest"
+; Check for use of the deprecated floating point operators
+float_operator_check="skip-unittest"
+; Check number literals for readability
+number_style_check="disabled"
+; Checks that opEquals, opCmp, toHash, and toString are either const, immutable
+; , or inout.
+object_const_check="disabled"
+; Checks for .. expressions where the left side is larger than the right.
+backwards_range_check="skip-unittest"
+; Checks for if statements whose 'then' block is the same as the 'else' block
+if_else_same_check="skip-unittest"
+; Checks for some problems with constructors
+constructor_check="skip-unittest"
+; Checks for unused variables and function parameters
+unused_variable_check="disabled"
+; Checks for unused labels
+unused_label_check="skip-unittest"
+; Checks for duplicate attributes
+duplicate_attribute="skip-unittest"
+; Checks that opEquals and toHash are both defined or neither are defined
+opequals_tohash_check="disabled"
+; Checks for subtraction from .length properties
+length_subtraction_check="disabled"
+; Checks for methods or properties whose names conflict with built-in propertie
+; s
+builtin_property_names_check="skip-unittest"
+; Checks for confusing code in inline asm statements
+asm_style_check="skip-unittest"
+; Checks for confusing logical operator precedence
+logical_precedence_check="skip-unittest"
+; Checks for undocumented public declarations
+undocumented_declaration_check="disabled"
+; Checks for poor placement of function attributes
+function_attribute_check="skip-unittest"
+; Checks for use of the comma operator
+comma_expression_check="skip-unittest"
+; Checks for local imports that are too broad
+local_import_check="disabled"
+; Checks for variables that could be declared immutable
+could_be_immutable_check="disabled"
+; Checks for redundant expressions in if statements
+redundant_if_check="skip-unittest"
+; Checks for redundant parenthesis
+redundant_parens_check="skip-unittest"
+; Checks for mismatched argument and parameter names
+mismatched_args_check="skip-unittest"
+; Checks for labels with the same name as variables
+label_var_same_name_check="disabled"
+; Checks for lines longer than 120 characters
+long_line_check="skip-unittest"
+; Checks for assignment to auto-ref function parameters
+auto_ref_assignment_check="disabled"
+; Checks for incorrect infinite range definitions
+incorrect_infinite_range_check="skip-unittest"
+; Checks for asserts that are always true
+useless_assert_check="skip-unittest"
+; Check for uses of the old-style alias syntax
+alias_syntax_check="disabled"
+; Checks for else if that should be else static if
+static_if_else_check="skip-unittest"
+; Check for unclear lambda syntax
+lambda_return_check="skip-unittest"
+; Check for auto function without return statement
+auto_function_check="skip-unittest"
+; Check for sortedness of imports
+imports_sortedness="disabled"
+; Check for explicitly annotated unittests
+explicitly_annotated_unittests="disabled"
+; Check for useless usage of the final attribute
+final_attribute_check="skip-unittest"

dub.json

@@ -1,6 +1,6 @@
 {
 	"name": "tanya",
-	"description": "General purpose, @nogc library",
+	"description": "General purpose, @nogc library. Containers, networking, memory management, utilities",
 	"license": "MPL-2.0",
 	"copyright": "(c) Eugene Wissner <info@caraus.de>",
 	"authors": [

source/tanya/async/event/epoll.d

@@ -2,7 +2,9 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-/**
+/*
+ * Event loop implementation for Linux.
+ *
  * Copyright: Eugene Wissner 2016-2017.
  * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
  *                  Mozilla Public License, v. 2.0).
@@ -10,7 +12,10 @@
  */
 module tanya.async.event.epoll;
 
-version (linux):
+version (D_Ddoc)
+{
+}
+else version (linux):
 
 public import core.sys.linux.epoll;
 import tanya.async.protocol;
@@ -18,7 +23,7 @@ import tanya.async.event.selector;
 import tanya.async.loop;
 import tanya.async.transport;
 import tanya.async.watcher;
-import tanya.container.vector;
+import tanya.container.array;
 import tanya.memory;
 import tanya.memory.mmappool;
 import tanya.network.socket;
@@ -37,7 +42,7 @@ extern (C) nothrow @nogc
 final class EpollLoop : SelectorLoop
 {
     protected int fd;
-	private Vector!epoll_event events;
+    private Array!epoll_event events;
 
     /**
      * Initializes the loop.
@@ -49,7 +54,7 @@ final class EpollLoop : SelectorLoop
             throw defaultAllocator.make!BadLoopException("epoll initialization failed");
         }
         super();
-		events = Vector!epoll_event(maxEvents, MmapPool.instance);
+        events = Array!epoll_event(maxEvents, MmapPool.instance);
     }
 
     /**

source/tanya/async/event/iocp.d

@@ -2,7 +2,9 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-/**
+/*
+ * Event loop implementation for Windows.
+ *
  * Copyright: Eugene Wissner 2016-2017.
  * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
  *                  Mozilla Public License, v. 2.0).
@@ -10,7 +12,10 @@
  */
 module tanya.async.event.iocp;
 
-version (Windows):
+version (D_Ddoc)
+{
+}
+else version (Windows):
 
 import tanya.container.buffer;
 import tanya.async.loop;
@@ -226,8 +231,8 @@ final class IOCPLoop : Loop
                 return false;
             }
         }
-		if (!(oldEvents & Event.read) && (events & Event.read)
-			|| !(oldEvents & Event.write) && (events & Event.write))
+        if ((!(oldEvents & Event.read) && (events & Event.read))
+            || (!(oldEvents & Event.write) && (events & Event.write)))
         {
             auto transport = cast(StreamTransport) watcher;
             assert(transport !is null);

source/tanya/async/event/kqueue.d

@@ -2,7 +2,9 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-/**
+/*
+ * Event loop implementation for *BSD.
+ *
  * Copyright: Eugene Wissner 2016-2017.
  * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
  *                  Mozilla Public License, v. 2.0).
@@ -10,7 +12,10 @@
  */
 module tanya.async.event.kqueue;
 
-version (OSX)
+version (D_Ddoc)
+{
+}
+else version (OSX)
 {
     version = MacBSD;
 }
@@ -50,7 +55,7 @@ import tanya.async.event.selector;
 import tanya.async.loop;
 import tanya.async.transport;
 import tanya.async.watcher;
-import tanya.container.vector;
+import tanya.container.array;
 import tanya.memory;
 import tanya.memory.mmappool;
 import tanya.network.socket;
@@ -116,8 +121,8 @@ extern(C) int kevent(int kq, const kevent_t *changelist, int nchanges,
 final class KqueueLoop : SelectorLoop
 {
     protected int fd;
-	private Vector!kevent_t events;
-	private Vector!kevent_t changes;
+    private Array!kevent_t events;
+    private Array!kevent_t changes;
     private size_t changeCount;
 
     /**
@@ -139,8 +144,8 @@ final class KqueueLoop : SelectorLoop
             throw make!BadLoopException(defaultAllocator,
                                         "kqueue initialization failed");
         }
-		events = Vector!kevent_t(64, MmapPool.instance);
-		changes = Vector!kevent_t(64, MmapPool.instance);
+        events = Array!kevent_t(64, MmapPool.instance);
+        changes = Array!kevent_t(64, MmapPool.instance);
     }
 
     /**
@@ -151,7 +156,7 @@ final class KqueueLoop : SelectorLoop
         close(fd);
     }
 
-	private void set(socket_t socket, short filter, ushort flags) @nogc
+    private void set(SocketType socket, short filter, ushort flags) @nogc
     {
         if (changes.length <= changeCount)
         {

source/tanya/async/event/selector.d

@@ -2,7 +2,9 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-/**
+/*
+ * This module contains base implementations for reactor event loops.
+ *
  * Copyright: Eugene Wissner 2016-2017.
  * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
  *                  Mozilla Public License, v. 2.0).
@@ -10,14 +12,17 @@
  */
 module tanya.async.event.selector;
 
-version (Posix):
+version (D_Ddoc)
+{
+}
+else version (Posix):
 
 import tanya.async.loop;
 import tanya.async.protocol;
 import tanya.async.transport;
 import tanya.async.watcher;
 import tanya.container.buffer;
-import tanya.container.vector;
+import tanya.container.array;
 import tanya.memory;
 import tanya.memory.mmappool;
 import tanya.network.socket;
@@ -78,7 +83,8 @@ package class StreamTransport : SocketWatcher, DuplexTransport, SocketTransport
         return cast(ConnectedSocket) socket_;
     }
 
-	private @property void socket(ConnectedSocket socket) pure nothrow @safe @nogc
+    private @property void socket(ConnectedSocket socket)
+    pure nothrow @safe @nogc
     in
     {
         assert(socket !is null);
@@ -133,7 +139,9 @@ package class StreamTransport : SocketWatcher, DuplexTransport, SocketTransport
     void close() @nogc
     {
         closing = true;
-		loop.reify(this, EventMask(Event.read, Event.write), EventMask(Event.write));
+        loop.reify(this,
+                   EventMask(Event.read, Event.write),
+                   EventMask(Event.write));
     }
 
     /**
@@ -205,20 +213,20 @@ package class StreamTransport : SocketWatcher, DuplexTransport, SocketTransport
 abstract class SelectorLoop : Loop
 {
     /// Pending connections.
-	protected Vector!SocketWatcher connections;
+    protected Array!SocketWatcher connections;
 
     this() @nogc
     {
         super();
-		connections = Vector!SocketWatcher(maxEvents, MmapPool.instance);
+        connections = Array!SocketWatcher(maxEvents, MmapPool.instance);
     }
 
     ~this() @nogc
     {
         foreach (ref connection; connections)
         {
-			// We want to free only the transports. ConnectionWatcher are created by the
-			// user and should be freed by himself.
+            // We want to free only the transports. ConnectionWatcher are
+            // created by the user and should be freed by himself.
             if (cast(StreamTransport) connection !is null)
             {
                 MmapPool.instance.dispose(connection);

source/tanya/async/iocp.d

@@ -3,6 +3,10 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 /**
+ * This module provides API for Windows I/O Completion Ports.
+ *
+ * Note: Available only on Windows.
+ *
  * Copyright: Eugene Wissner 2016-2017.
  * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
  *                  Mozilla Public License, v. 2.0).
@@ -10,7 +14,26 @@
  */
 module tanya.async.iocp;
 
-version (Windows):
+version (Windows)
+{
+    version = WindowsDoc;
+}
+else version (D_Ddoc)
+{
+    version = WindowsDoc;
+    version (Windows)
+    {
+    }
+    else
+    {
+        private struct OVERLAPPED
+        {
+        }
+        private alias HANDLE = void*;
+    }
+}
+
+version (WindowsDoc):
 
 import core.sys.windows.winbase;
 import core.sys.windows.windef;

source/tanya/async/loop.d

@@ -3,10 +3,8 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 /**
- * Copyright: Eugene Wissner 2016-2017.
- * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
- *                  Mozilla Public License, v. 2.0).
- * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
+ * Interface for the event loop implementations and the default event loop
+ * chooser.
  *
  * ---
  * import tanya.async;
@@ -38,11 +36,11 @@
  *
  *  version (Windows)
  *  {
- * 		auto sock = defaultAllocator.make!OverlappedStreamSocket(AddressFamily.INET);
+ *      auto sock = defaultAllocator.make!OverlappedStreamSocket(AddressFamily.inet);
  *  }
  *  else
  *  {
- * 		auto sock = defaultAllocator.make!StreamSocket(AddressFamily.INET);
+ *      auto sock = defaultAllocator.make!StreamSocket(AddressFamily.inet);
  *      sock.blocking = false;
  *  }
  *
@@ -61,6 +59,11 @@
  *  defaultAllocator.dispose(address);
  * }
  * ---
+ *
+ * Copyright: Eugene Wissner 2016-2017.
+ * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
+ *                  Mozilla Public License, v. 2.0).
+ * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
  */
 module tanya.async.loop;
 
@@ -79,6 +82,9 @@ import tanya.network.socket;
 version (DisableBackends)
 {
 }
+else version (D_Ddoc)
+{
+}
 else version (linux)
 {
     import tanya.async.event.epoll;
@@ -109,6 +115,30 @@ else version (DragonFlyBSD)
 {
     version = Kqueue;
 }
+version (unittest)
+{
+    final class TestLoop : Loop
+    {
+        override protected bool reify(SocketWatcher watcher,
+                                      EventMask oldEvents,
+                                      EventMask events) @nogc
+        {
+            return true;
+        }
+
+        override protected void poll() @nogc
+        {
+            assert(!this.done);
+            unloop();
+        }
+
+        override protected @property uint maxEvents()
+        const pure nothrow @safe @nogc
+        {
+            return 64U;
+        }
+    }
+}
 
 /**
  * Events.
@@ -129,7 +159,7 @@ alias EventMask = BitFlags!Event;
  */
 abstract class Loop
 {
-	private bool done;
+    private bool done = true;
 
     /// Pending watchers.
     protected Queue!Watcher pendings;
@@ -144,6 +174,14 @@ abstract class Loop
         return 128U;
     }
 
+    private unittest
+    {
+        auto loop = defaultAllocator.make!TestLoop;
+        assert(loop.maxEvents == 64);
+
+        defaultAllocator.dispose(loop);
+    }
+
     /**
      * Initializes the loop.
      */
@@ -168,18 +206,18 @@ abstract class Loop
      */
     void run() @nogc
     {
-		done = false;
+        this.done = false;
         do
         {
             poll();
 
             // Invoke pendings
-			foreach (ref w; pendings)
+            foreach (ref w; this.pendings)
             {
                 w.invoke();
             }
         }
-		while (!done);
+        while (!this.done);
     }
 
     /**
@@ -187,7 +225,32 @@ abstract class Loop
      */
     void unloop() @safe pure nothrow @nogc
     {
-		done = true;
+        this.done = true;
+    }
+
+    private unittest
+    {
+        auto loop = defaultAllocator.make!TestLoop;
+        assert(loop.done);
+
+        loop.run();
+        assert(loop.done);
+
+        defaultAllocator.dispose(loop);
+    }
+
+    private unittest
+    {
+        auto loop = defaultAllocator.make!TestLoop;
+        auto watcher = defaultAllocator.make!DummyWatcher;
+        loop.pendings.enqueue(watcher);
+
+        assert(!watcher.invoked);
+        loop.run();
+        assert(watcher.invoked);
+
+        defaultAllocator.dispose(loop);
+        defaultAllocator.dispose(watcher);
     }
 
     /**
@@ -266,6 +329,17 @@ abstract class Loop
         blockTime_ = blockTime;
     }
 
+    private unittest
+    {
+        auto loop = defaultAllocator.make!TestLoop;
+        assert(loop.blockTime == 1.dur!"minutes");
+
+        loop.blockTime = 2.dur!"minutes";
+        assert(loop.blockTime == 2.dur!"minutes");
+
+        defaultAllocator.dispose(loop);
+    }
+
     /**
      * Does the actual polling.
      */
@@ -344,3 +418,16 @@ body
 }
 
 private Loop defaultLoop_;
+
+private unittest
+{
+    auto oldLoop = defaultLoop_;
+    auto loop = defaultAllocator.make!TestLoop;
+
+    defaultLoop = loop;
+    assert(defaultLoop_ is loop);
+    assert(defaultLoop is loop);
+
+    defaultLoop_ = oldLoop;
+    defaultAllocator.dispose(loop);
+}

source/tanya/async/package.d

@@ -3,6 +3,8 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 /**
+ * This package provides asynchronous capabilities.
+ *
  * Copyright: Eugene Wissner 2016-2017.
  * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
  *                  Mozilla Public License, v. 2.0).

source/tanya/async/protocol.d

@@ -3,6 +3,12 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 /**
+ * This module contains protocol which handle data in asynchronous
+ * applications.
+ *
+ * When an event from the network arrives, a protocol method gets
+ * called and can respond to the event.
+ *
  * Copyright: Eugene Wissner 2016-2017.
  * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
  *                  Mozilla Public License, v. 2.0).

source/tanya/async/transport.d

@@ -3,6 +3,9 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 /**
+ * This module contains transports which are responsible for data dilvery
+ * between two parties of an asynchronous communication.
+ *
  * Copyright: Eugene Wissner 2016-2017.
  * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
  *                  Mozilla Public License, v. 2.0).

source/tanya/async/watcher.d

@@ -3,6 +3,8 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 /**
+ * Watchers register user's interest in some event.
+ *
  * Copyright: Eugene Wissner 2016-2017.
  * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
  *                  Mozilla Public License, v. 2.0).
@@ -36,6 +38,19 @@ abstract class Watcher
     void invoke() @nogc;
 }
 
+version (unittest)
+{
+    final class DummyWatcher : Watcher
+    {
+        bool invoked;
+
+        override void invoke() @nogc
+        {
+            this.invoked = true;
+        }
+    }
+}
+
 /**
  * Socket watcher.
  */

source/tanya/container/buffer.d

@@ -3,6 +3,8 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 /**
+ * This module contains buffers designed for C-style input/output APIs.
+ *
  * Copyright: Eugene Wissner 2016-2017.
  * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
  *                  Mozilla Public License, v. 2.0).

source/tanya/container/entry.d

@@ -12,11 +12,100 @@
  */
 module tanya.container.entry;
 
+import std.traits;
+import tanya.typecons;
+
 package struct SEntry(T)
 {
-    /// Item content.
+    // Item content.
     T content;
 
-    /// Next item.
+    // Next item.
     SEntry* next;
 }
+
+package struct DEntry(T)
+{
+    // Item content.
+    T content;
+
+    // Previous and next item.
+    DEntry* next, prev;
+}
+
+package struct HashEntry(K, V)
+{
+    this(ref K key, ref V value)
+    {
+        this.pair = Pair!(K, V)(key, value);
+    }
+
+    Pair!(K, V) pair;
+    HashEntry* next;
+}
+
+package enum BucketStatus : byte
+{
+    deleted = -1,
+    empty = 0,
+    used = 1,
+}
+
+package struct Bucket(T)
+{
+    this(ref T content)
+    {
+        this.content = content;
+    }
+
+    @property void content(ref T content)
+    {
+        this.content_ = content;
+        this.status = BucketStatus.used;
+    }
+
+    @property ref inout(T) content() inout
+    {
+        return this.content_;
+    }
+
+    bool opEquals(ref T content)
+    {
+        if (this.status == BucketStatus.used && this.content == content)
+        {
+            return true;
+        }
+        return false;
+    }
+
+    bool opEquals(ref T content) const
+    {
+        if (this.status == BucketStatus.used && this.content == content)
+        {
+            return true;
+        }
+        return false;
+    }
+
+    bool opEquals(ref typeof(this) that)
+    {
+        return this.content == that.content && this.status == that.status;
+    }
+
+    bool opEquals(ref typeof(this) that) const
+    {
+        return this.content == that.content && this.status == that.status;
+    }
+
+    void remove()
+    {
+        static if (hasElaborateDestructor!T)
+        {
+            destroy(this.content);
+        }
+        this.status = BucketStatus.deleted;
+    }
+
+    T content_;
+    BucketStatus status = BucketStatus.empty;
+}

source/tanya/container/package.d

@@ -12,7 +12,31 @@
  */
 module tanya.container;
 
+public import tanya.container.array;
 public import tanya.container.buffer;
+public import tanya.container.set;
 public import tanya.container.list;
-public import tanya.container.vector;
+public import tanya.container.string;
 public import tanya.container.queue;
+
+/**
+ * Thrown if $(D_PSYMBOL Set) cannot insert a new element because the container
+ * is full.
+ */
+class HashContainerFullException : Exception
+{
+    /**
+     * Params:
+     *  msg  = The message for the exception.
+     *  file = The file where the exception occurred.
+     *  line = The line number where the exception occurred.
+     *  next = The previous exception in the chain of exceptions, if any.
+     */
+    this(string msg,
+         string file = __FILE__,
+         size_t line = __LINE__,
+         Throwable next = null) @nogc @safe pure nothrow
+    {
+        super(msg, file, line, next);
+    }
+}

source/tanya/container/set.d

@@ -0,0 +1,710 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * This module implements a $(D_PSYMBOL Set) container that stores unique
+ * values without any particular order.
+ *
+ * Copyright: Eugene Wissner 2017.
+ * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
+ *                  Mozilla Public License, v. 2.0).
+ * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
+ */
+module tanya.container.set;
+
+import std.algorithm.mutation;
+import std.traits;
+import tanya.container;
+import tanya.container.entry;
+import tanya.memory;
+
+/**
+ * Bidirectional range that iterates over the $(D_PSYMBOL Set)'s values.
+ *
+ * Params:
+ *  E = Element type.
+ */
+struct Range(E)
+{
+    static if (isMutable!E)
+    {
+        private alias DataRange = Array!(Bucket!(Unqual!E)).Range;
+    }
+    else
+    {
+        private alias DataRange = Array!(Bucket!(Unqual!E)).ConstRange;
+    }
+    private DataRange dataRange;
+
+    @disable this();
+
+    private this(DataRange dataRange)
+    {
+        while (!dataRange.empty && dataRange.front.status != BucketStatus.used)
+        {
+            dataRange.popFront();
+        }
+        while (!dataRange.empty && dataRange.back.status != BucketStatus.used)
+        {
+            dataRange.popBack();
+        }
+        this.dataRange = dataRange;
+    }
+
+    @property Range save()
+    {
+        return this;
+    }
+
+    @property bool empty() const
+    {
+        return this.dataRange.empty();
+    }
+
+    @property void popFront()
+    in
+    {
+        assert(!this.dataRange.empty);
+        assert(this.dataRange.front.status == BucketStatus.used);
+    }
+    out
+    {
+        assert(this.dataRange.empty
+            || this.dataRange.back.status == BucketStatus.used);
+    }
+    body
+    {
+        do
+        {
+            dataRange.popFront();
+        }
+        while (!dataRange.empty && dataRange.front.status != BucketStatus.used);
+    }
+
+    @property void popBack()
+    in
+    {
+        assert(!this.dataRange.empty);
+        assert(this.dataRange.back.status == BucketStatus.used);
+    }
+    out
+    {
+        assert(this.dataRange.empty
+            || this.dataRange.back.status == BucketStatus.used);
+    }
+    body
+    {
+        do
+        {
+            dataRange.popBack();
+        }
+        while (!dataRange.empty && dataRange.back.status != BucketStatus.used);
+    }
+
+    @property ref inout(E) front() inout
+    in
+    {
+        assert(!this.dataRange.empty);
+        assert(this.dataRange.front.status == BucketStatus.used);
+    }
+    body
+    {
+        return dataRange.front.content;
+    }
+
+    @property ref inout(E) back() inout
+    in
+    {
+        assert(!this.dataRange.empty);
+        assert(this.dataRange.back.status == BucketStatus.used);
+    }
+    body
+    {
+        return dataRange.back.content;
+    }
+
+    Range opIndex()
+    {
+        return typeof(return)(this.dataRange[]);
+    }
+
+    Range!(const E) opIndex() const
+    {
+        return typeof(return)(this.dataRange[]);
+    }
+}
+
+/**
+ * Set is a data structure that stores unique values without any particular
+ * order.
+ *
+ * This $(D_PSYMBOL Set) is implemented using closed hashing. Hash collisions
+ * are resolved with linear probing.
+ *
+ * Currently works only with integral types.
+ *
+ * Params:
+ *  T = Element type.
+ */
+struct Set(T)
+    if (isIntegral!T || is(Unqual!T == bool))
+{
+    /// The range types for $(D_PSYMBOL Set).
+    alias Range = .Range!T;
+
+    /// Ditto.
+    alias ConstRange = .Range!(const T);
+
+    invariant
+    {
+        assert(this.lengthIndex < primes.length);
+        assert(this.data.length == 0
+            || this.data.length == primes[this.lengthIndex]);
+    }
+
+    /**
+     * Constructor.
+     *
+     * Params:
+     *  n         = Minimum number of buckets.
+     *  allocator = Allocator.
+     *
+     * Precondition: $(D_INLINECODE allocator !is null).
+     */
+    this(const size_t n, shared Allocator allocator = defaultAllocator)
+    in
+    {
+        assert(allocator !is null);
+    }
+    body
+    {
+        this(allocator);
+        rehash(n);
+    }
+
+    /// Ditto.
+    this(shared Allocator allocator)
+    in
+    {
+        assert(allocator !is null);
+    }
+    body
+    {
+        this.data = typeof(this.data)(allocator);
+    }
+
+    ///
+    unittest
+    {
+        {
+            auto set = Set!int(defaultAllocator);
+            assert(set.capacity == 0);
+        }
+        {
+            auto set = Set!int(8);
+            assert(set.capacity == 13);
+        }
+    }
+
+    /**
+     * Initializes this $(D_PARAM Set) from another one.
+     *
+     * If $(D_PARAM init) is passed by reference, it will be copied.
+     * If $(D_PARAM init) is passed by value, it will be moved.
+     *
+     * Params:
+     *  S         = Source set type.
+     *  init      = Source set.
+     *  allocator = Allocator.
+     */
+    this(S)(ref S init, shared Allocator allocator = defaultAllocator)
+        if (is(Unqual!S == Set))
+    in
+    {
+        assert(allocator !is null);
+    }
+    body
+    {
+        this.data = typeof(this.data)(init.data, allocator);
+    }
+
+    /// Ditto.
+    this(S)(S init, shared Allocator allocator = defaultAllocator)
+        if (is(S == Set))
+    in
+    {
+        assert(allocator !is null);
+    }
+    body
+    {
+        this.data = typeof(this.data)(move(init.data), allocator);
+        this.lengthIndex = init.lengthIndex;
+        init.lengthIndex = 0;
+    }
+
+    /**
+     * Assigns another set.
+     *
+     * If $(D_PARAM that) is passed by reference, it will be copied.
+     * If $(D_PARAM that) is passed by value, it will be moved.
+     *
+     * Params:
+     *  S    = Content type.
+     *  that = The value should be assigned.
+     *
+     * Returns: $(D_KEYWORD this).
+     */
+    ref typeof(this) opAssign(S)(ref S that)
+        if (is(Unqual!S == Set))
+    {
+        this.data = that.data;
+        this.lengthIndex = that.lengthIndex;
+        return this;
+    }
+
+    /// Ditto.
+    ref typeof(this) opAssign(S)(S that) @trusted
+        if (is(S == Set))
+    {
+        swap(this.data, that.data);
+        swap(this.lengthIndex, that.lengthIndex);
+        return this;
+    }
+
+    /**
+     * Returns: Used allocator.
+     *
+     * Postcondition: $(D_INLINECODE allocator !is null)
+     */
+    @property shared(Allocator) allocator() const
+    out (allocator)
+    {
+        assert(allocator !is null);
+    }
+    body
+    {
+        return cast(shared Allocator) this.data.allocator;
+    }
+
+    /**
+     * Maximum amount of elements this $(D_PSYMBOL Set) can hold without
+     * resizing and rehashing. Note that it doesn't mean that the
+     * $(D_PSYMBOL Set) will hold $(I exactly) $(D_PSYMBOL capacity) elements.
+     * $(D_PSYMBOL capacity) tells the size of the container under a best-case
+     * distribution of elements.
+     *
+     * Returns: $(D_PSYMBOL Set) capacity.
+     */
+    @property size_t capacity() const
+    {
+        return this.data.length;
+    }
+
+    ///
+    unittest
+    {
+        Set!int set;
+        assert(set.capacity == 0);
+
+        set.insert(8);
+        assert(set.capacity == 3);
+    }
+
+    /**
+     * Iterates over the $(D_PSYMBOL Set) and counts the elements.
+     *
+     * Returns: Count of elements within the $(D_PSYMBOL Set).
+     */
+    @property size_t length() const
+    {
+        size_t count;
+        foreach (ref e; this.data[])
+        {
+            if (e.status == BucketStatus.used)
+            {
+                ++count;
+            }
+        }
+        return count;
+    }
+
+    ///
+    unittest
+    {
+        Set!int set;
+        assert(set.length == 0);
+
+        set.insert(8);
+        assert(set.length == 1);
+    }
+
+    private static const size_t[41] primes = [
+        3, 7, 13, 23, 29, 37, 53, 71, 97, 131, 163, 193, 239, 293, 389, 521,
+        769, 919, 1103, 1327, 1543, 2333, 3079, 4861, 6151, 12289, 24593,
+        49157, 98317, 196613, 393241, 786433, 1572869, 3145739, 6291469,
+        12582917, 25165843, 139022417, 282312799, 573292817, 1164186217,
+    ];
+
+    /// The maximum number of buckets the container can have.
+    enum size_t maxBucketCount = primes[$ - 1];
+
+    static private size_t calculateHash(ref T value)
+    {
+        static if (isIntegral!T || isSomeChar!T || is(T == bool))
+        {
+            return (cast(size_t) value);
+        }
+        else
+        {
+            static assert(false);
+        }
+    }
+
+    static private size_t locateBucket(ref const DataType buckets, size_t hash)
+    {
+        return hash % buckets.length;
+    }
+
+    private enum InsertStatus : byte
+    {
+        found = -1,
+        failed = 0,
+        added = 1,
+    }
+
+    /*
+     * Inserts the value in an empty or deleted bucket. If the value is
+     * already in there, does nothing and returns InsertStatus.found. If the
+     * hash array is full returns InsertStatus.failed.
+     */
+    private InsertStatus insertInUnusedBucket(ref T value)
+    {
+        auto bucketPosition = locateBucket(this.data, calculateHash(value));
+
+        foreach (ref e; this.data[bucketPosition .. $])
+        {
+            if (e == value) // Already in the set.
+            {
+                return InsertStatus.found;
+            }
+            else if (e.status != BucketStatus.used) // Insert the value.
+            {
+                e.content = value;
+                return InsertStatus.added;
+            }
+        }
+        return InsertStatus.failed;
+    }
+
+    /**
+     * Inserts a new element.
+     *
+     * Params:
+     *  value = Element value.
+     *
+     * Returns: Amount of new elements inserted.
+     *
+     * Throws: $(D_PSYMBOL HashContainerFullException) if the insertion failed.
+     */
+    size_t insert(T value)
+    {
+        if (this.data.length == 0)
+        {
+            this.data = DataType(primes[0], allocator);
+        }
+
+        InsertStatus status = insertInUnusedBucket(value);
+        for (; !status; status = insertInUnusedBucket(value))
+        {
+            if ((this.primes.length - 1) == this.lengthIndex)
+            {
+                throw make!HashContainerFullException(defaultAllocator,
+                                                      "Set is full");
+            }
+            rehashToSize(this.lengthIndex + 1);
+        }
+        return status == InsertStatus.added;
+    }
+
+    ///
+    unittest
+    {
+        Set!int set;
+        assert(8 !in set);
+
+        assert(set.insert(8) == 1);
+        assert(set.length == 1);
+        assert(8 in set);
+
+        assert(set.insert(8) == 0);
+        assert(set.length == 1);
+        assert(8 in set);
+
+        assert(set.remove(8));
+        assert(set.insert(8) == 1);
+    }
+
+    /**
+     * Removes an element.
+     *
+     * Params:
+     *  value = Element value.
+     *
+     * Returns: Number of elements removed, which is in the container with
+     *          unique values `1` if an element existed, and `0` otherwise.
+     */
+    size_t remove(T value)
+    {
+        if (this.data.length == 0)
+        {
+            return 0;
+        }
+
+        auto bucketPosition = locateBucket(this.data, calculateHash(value));
+        foreach (ref e; this.data[bucketPosition .. $])
+        {
+            if (e == value) // Found.
+            {
+                e.remove();
+                return 1;
+            }
+            else if (e.status == BucketStatus.empty)
+            {
+                break;
+            }
+        }
+        return 0;
+    }
+
+    ///
+    unittest
+    {
+        Set!int set;
+        assert(8 !in set);
+
+        set.insert(8);
+        assert(8 in set);
+
+        assert(set.remove(8) == 1);
+        assert(set.remove(8) == 0);
+        assert(8 !in set);
+    }
+
+    /**
+     * $(D_KEYWORD in) operator.
+     *
+     * Params:
+     *  value = Element to be searched for.
+     *
+     * Returns: $(D_KEYWORD true) if the given element exists in the container,
+     *          $(D_KEYWORD false) otherwise.
+     */
+    bool opBinaryRight(string op : "in")(auto ref T value)
+    {
+        if (this.data.length == 0)
+        {
+            return 0;
+        }
+
+        auto bucketPosition = locateBucket(this.data, calculateHash(value));
+        foreach (ref e; this.data[bucketPosition .. $])
+        {
+            if (e == value) // Found.
+            {
+                return true;
+            }
+            else if (e.status == BucketStatus.empty)
+            {
+                break;
+            }
+        }
+        return false;
+    }
+
+    /// Ditto.
+    bool opBinaryRight(string op : "in")(auto ref const T value) const
+    {
+        if (this.data.length == 0)
+        {
+            return 0;
+        }
+
+        auto bucketPosition = locateBucket(this.data, calculateHash(value));
+        foreach (ref e; this.data[bucketPosition .. $])
+        {
+            if (e.status == BucketStatus.used && e.content == value) // Found.
+            {
+                return true;
+            }
+            else if (e.status == BucketStatus.empty)
+            {
+                break;
+            }
+        }
+        return false;
+    }
+
+    ///
+    unittest
+    {
+        Set!int set;
+
+        assert(5 !in set);
+        set.insert(5);
+        assert(5 in set);
+    }
+
+    /**
+     * Sets the number of buckets in the container to at least $(D_PARAM n)
+     * and rearranges all the elements according to their hash values.
+     *
+     * If $(D_PARAM n) is greater than the current $(D_PSYMBOL capacity)
+     * and lower than or equal to $(D_PSYMBOL maxBucketCount), a rehash is
+     * forced.
+     *
+     * If $(D_PARAM n) is greater than $(D_PSYMBOL maxBucketCount),
+     * $(D_PSYMBOL maxBucketCount) is used instead as a new number of buckets.
+     *
+     * If $(D_PARAM n) is equal to the current $(D_PSYMBOL capacity), rehashing
+     * is forced without resizing the container.
+     *
+     * If $(D_PARAM n) is lower than the current $(D_PSYMBOL capacity), the
+     * function may have no effect.
+     *
+     * Rehashing is automatically performed whenever the container needs space
+     * to insert new elements.
+     *
+     * Params:
+     *  n = Minimum number of buckets.
+     */
+    void rehash(const size_t n)
+    {
+        size_t lengthIndex;
+        for (; lengthIndex < primes.length; ++lengthIndex)
+        {
+            if (primes[lengthIndex] >= n)
+            {
+                break;
+            }
+        }
+        rehashToSize(lengthIndex);
+    }
+
+    // Takes an index in the primes array.
+    private void rehashToSize(const size_t n)
+    {
+        auto storage = DataType(primes[n], allocator);
+        DataLoop: foreach (ref e1; this.data[])
+        {
+            if (e1.status == BucketStatus.used)
+            {
+                auto bucketPosition = locateBucket(storage,
+                                                   calculateHash(e1.content));
+
+                foreach (ref e2; storage[bucketPosition .. $])
+                {
+                    if (e2.status != BucketStatus.used) // Insert the value.
+                    {
+                        e2.content = e1.content;
+                        continue DataLoop;
+                    }
+                }
+                return; // Rehashing failed.
+            }
+        }
+        move(storage, this.data);
+        this.lengthIndex = n;
+    }
+
+    /**
+     * Returns: A bidirectional range that iterates over the $(D_PSYMBOL Set)'s
+     *          elements.
+     */
+    Range opIndex()
+    {
+        return typeof(return)(this.data[]);
+    }
+
+    /// Ditto.
+    ConstRange opIndex() const
+    {
+        return typeof(return)(this.data[]);
+    }
+
+    ///
+    unittest
+    {
+        Set!int set;
+        assert(set[].empty);
+
+        set.insert(8);
+        assert(!set[].empty);
+        assert(set[].front == 8);
+        assert(set[].back == 8);
+
+        set.remove(8);
+        assert(set[].empty);
+    }
+
+    private alias DataType = Array!(Bucket!T);
+    private DataType data;
+    private size_t lengthIndex;
+}
+
+// Basic insertion logic.
+private unittest
+{
+    Set!int set;
+
+    assert(set.insert(5) == 1);
+    assert(set.data[0].status == BucketStatus.empty);
+    assert(set.data[1].status == BucketStatus.empty);
+    assert(set.data[2].content == 5 && set.data[2].status == BucketStatus.used);
+    assert(set.data.length == 3);
+
+    assert(set.insert(5) == 0);
+    assert(set.data[0].status == BucketStatus.empty);
+    assert(set.data[1].status == BucketStatus.empty);
+    assert(set.data[2].content == 5 && set.data[2].status == BucketStatus.used);
+    assert(set.data.length == 3);
+
+    assert(set.insert(9) == 1);
+    assert(set.data[0].content == 9 && set.data[0].status == BucketStatus.used);
+    assert(set.data[1].status == BucketStatus.empty);
+    assert(set.data[2].content == 5 && set.data[2].status == BucketStatus.used);
+    assert(set.data.length == 3);
+
+    assert(set.insert(7) == 1);
+    assert(set.insert(8) == 1);
+    assert(set.data[0].content == 7);
+    assert(set.data[1].content == 8);
+    assert(set.data[2].content == 9);
+    assert(set.data[3].status == BucketStatus.empty);
+    assert(set.data[5].content == 5);
+    assert(set.data.length == 7);
+
+    assert(set.insert(16) == 1);
+    assert(set.data[2].content == 9);
+    assert(set.data[3].content == 16);
+    assert(set.data[4].status == BucketStatus.empty);
+}
+
+// Static checks.
+private unittest
+{
+    import std.range.primitives;
+
+    static assert(isBidirectionalRange!(Set!int.ConstRange));
+    static assert(isBidirectionalRange!(Set!int.Range));
+
+    static assert(!isInfinite!(Set!int.Range));
+    static assert(!hasLength!(Set!int.Range));
+
+    static assert(is(Set!uint));
+    static assert(is(Set!long));
+    static assert(is(Set!ulong));
+    static assert(is(Set!short));
+    static assert(is(Set!ushort));
+    static assert(is(Set!bool));
+}

source/tanya/format/conv.d

@@ -0,0 +1,537 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * This module provides functions for converting between different types.
+ *
+ * Copyright: Eugene Wissner 2017.
+ * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
+ *                  Mozilla Public License, v. 2.0).
+ * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
+ */
+module tanya.format.conv;
+
+import std.traits;
+import tanya.memory;
+
+/**
+ * Thrown if a type conversion fails.
+ */
+final class ConvException : Exception
+{
+    /**
+     * Params:
+     *  msg  = The message for the exception.
+     *  file = The file where the exception occurred.
+     *  line = The line number where the exception occurred.
+     *  next = The previous exception in the chain of exceptions, if any.
+     */
+    this(string msg,
+         string file = __FILE__,
+         size_t line = __LINE__,
+         Throwable next = null) @nogc @safe pure nothrow
+    {
+        super(msg, file, line, next);
+    }
+}
+
+/**
+ * If the source type $(D_PARAM From) and the target type $(D_PARAM To) are
+ * equal, does nothing. If $(D_PARAM From) can be implicitly converted to
+ * $(D_PARAM To), just returns $(D_PARAM from).
+ *
+ * Params:
+ *  To = Target type.
+ *
+ * Returns: $(D_PARAM from).
+ */
+template to(To)
+{
+    /**
+     * Params:
+     *  From = Source type.
+     *  from = Source value.
+     */
+    ref To to(From)(ref From from)
+    if (is(To == From))
+    {
+        return from;
+    }
+
+    /// Ditto.
+    To to(From)(From from)
+    if (is(Unqual!To == Unqual!From) || (isNumeric!From && isFloatingPoint!To))
+    {
+        return from;
+    }
+}
+
+///
+pure nothrow @safe @nogc unittest
+{
+    auto val = 5.to!int();
+    assert(val == 5);
+    static assert(is(typeof(val) == int));
+}
+
+private pure nothrow @safe @nogc unittest
+{
+    int val = 5;
+    assert(val.to!int() == 5);
+}
+
+/**
+ * Performs checked conversion from an integral type $(D_PARAM From) to an
+ * integral type $(D_PARAM To).
+ *
+ * Params:
+ *  From = Source type.
+ *  To   = Target type.
+ *  from = Source value.
+ *
+ * Returns: $(D_PARAM from) converted to $(D_PARAM To).
+ *
+ * Throws: $(D_PSYMBOL ConvException) if $(D_PARAM from) is too small or too
+ *         large to be represented by $(D_PARAM To).
+ */
+To to(To, From)(From from)
+if (isIntegral!From
+ && isIntegral!To
+ && !is(Unqual!To == Unqual!From)
+ && !is(To == enum))
+{
+    static if ((isUnsigned!From && isSigned!To && From.sizeof == To.sizeof)
+            || From.sizeof > To.sizeof)
+    {
+        if (from > To.max)
+        {
+            throw make!ConvException(defaultAllocator,
+                                     "Positive integer overflow");
+        }
+    }
+    static if (isSigned!From)
+    {
+        static if (isUnsigned!To)
+        {
+            if (from < 0)
+            {
+                throw make!ConvException(defaultAllocator,
+                                         "Negative integer overflow");
+            }
+        }
+        else static if (From.sizeof > To.sizeof)
+        {
+            if (from < To.min)
+            {
+                throw make!ConvException(defaultAllocator,
+                                         "Negative integer overflow");
+            }
+        }
+    }
+    static if (From.sizeof <= To.sizeof)
+    {
+        return from;
+    }
+    else static if (isSigned!To)
+    {
+        return cast(To) from;
+    }
+    else
+    {
+        return from & To.max;
+    }
+}
+
+private pure nothrow @safe @nogc unittest
+{
+    // ubyte -> ushort
+    assert((cast(ubyte) 0).to!ushort == 0);
+    assert((cast(ubyte) 1).to!ushort == 1);
+    assert((cast(ubyte) (ubyte.max - 1)).to!ushort == ubyte.max - 1);
+    assert((cast(ubyte) ubyte.max).to!ushort == ubyte.max);
+
+    // ubyte -> short
+    assert((cast(ubyte) 0).to!short == 0);
+    assert((cast(ubyte) 1).to!short == 1);
+    assert((cast(ubyte) (ubyte.max - 1)).to!short == ubyte.max - 1);
+    assert((cast(ubyte) ubyte.max).to!short == ubyte.max);
+}
+
+private unittest
+{
+    // ubyte <- ushort
+    assert((cast(ushort) 0).to!ubyte == 0);
+    assert((cast(ushort) 1).to!ubyte == 1);
+    assert((cast(ushort) (ubyte.max - 1)).to!ubyte == ubyte.max - 1);
+    assert((cast(ushort) ubyte.max).to!ubyte == ubyte.max);
+
+    // ubyte <- short
+    assert((cast(short) 0).to!ubyte == 0);
+    assert((cast(short) 1).to!ubyte == 1);
+    assert((cast(short) (ubyte.max - 1)).to!ubyte == ubyte.max - 1);
+    assert((cast(short) ubyte.max).to!ubyte == ubyte.max);
+
+    // short <-> int
+    assert(short.min.to!int == short.min);
+    assert((short.min + 1).to!int == short.min + 1);
+    assert((cast(short) -1).to!int == -1);
+    assert((cast(short) 0).to!int == 0);
+    assert((cast(short) 1).to!int == 1);
+    assert((short.max - 1).to!int == short.max - 1);
+    assert(short.max.to!int == short.max);
+
+    assert((cast(int) short.min).to!short == short.min);
+    assert((cast(int) short.min + 1).to!short == short.min + 1);
+    assert((cast(int) -1).to!short == -1);
+    assert((cast(int) 0).to!short == 0);
+    assert((cast(int) 1).to!short == 1);
+    assert((cast(int) short.max - 1).to!short == short.max - 1);
+    assert((cast(int) short.max).to!short == short.max);
+
+    // uint <-> int
+    assert((cast(uint) 0).to!int == 0);
+    assert((cast(uint) 1).to!int == 1);
+    assert((cast(uint) (int.max - 1)).to!int == int.max - 1);
+    assert((cast(uint) int.max).to!int == int.max);
+
+    assert((cast(int) 0).to!uint == 0);
+    assert((cast(int) 1).to!uint == 1);
+    assert((cast(int) (int.max - 1)).to!uint == int.max - 1);
+    assert((cast(int) int.max).to!uint == int.max);
+}
+
+private unittest
+{
+    ConvException exception;
+    try
+    {
+        assert(int.min.to!short == int.min);
+    }
+    catch (ConvException e)
+    {
+        exception = e;
+    }
+    assert(exception !is null);
+    defaultAllocator.dispose(exception);
+}
+
+private unittest
+{
+    ConvException exception;
+    try
+    {
+        assert(int.max.to!short == int.max);
+    }
+    catch (ConvException e)
+    {
+        exception = e;
+    }
+    assert(exception !is null);
+    defaultAllocator.dispose(exception);
+}
+
+private unittest
+{
+    ConvException exception;
+    try
+    {
+        assert(uint.max.to!ushort == ushort.max);
+    }
+    catch (ConvException e)
+    {
+        exception = e;
+    }
+    assert(exception !is null);
+    defaultAllocator.dispose(exception);
+}
+
+private unittest
+{
+    ConvException exception;
+    try
+    {
+        assert((-1).to!uint == -1);
+    }
+    catch (ConvException e)
+    {
+        exception = e;
+    }
+    assert(exception !is null);
+    defaultAllocator.dispose(exception);
+}
+
+private @nogc unittest
+{
+    enum Test : int
+    {
+        one,
+        two,
+    }
+    assert(Test.one.to!int == 0);
+    assert(Test.two.to!int == 1);
+}
+
+/**
+ * Converts a number to a boolean.
+ *
+ * Params:
+ *  From = Source type.
+ *  To   = Target type.
+ *  from = Source value.
+ *
+ * Returns: $(D_KEYWORD true) if $(D_INLINECODE from > 0 && from <= 1),
+ *          otherwise $(D_KEYWORD false).
+ *
+ * Throws: $(D_PSYMBOL ConvException) if $(D_PARAM from) is greater than `1` or
+ *         less than `0`.
+ */
+To to(To, From)(From from)
+if (isNumeric!From && is(Unqual!To == bool) && !is(Unqual!To == Unqual!From))
+{
+    if (from == 0)
+    {
+        return false;
+    }
+    else if (from < 0)
+    {
+        throw make!ConvException(defaultAllocator,
+                                 "Negative number overflow");
+    }
+    else if (from <= 1)
+    {
+        return true;
+    }
+    throw make!ConvException(defaultAllocator,
+                             "Positive number overflow");
+}
+
+private @nogc unittest
+{
+    assert(0.0.to!bool == false);
+    assert(0.2.to!bool == true);
+    assert(0.5.to!bool == true);
+    assert(1.0.to!bool == true);
+
+    assert(0.to!bool == false);
+    assert(1.to!bool == true);
+}
+
+private @nogc unittest
+{
+    ConvException exception;
+    try
+    {
+        assert((-1).to!bool == true);
+    }
+    catch (ConvException e)
+    {
+        exception = e;
+    }
+    assert(exception !is null);
+    defaultAllocator.dispose(exception);
+}
+
+private @nogc unittest
+{
+    ConvException exception;
+    try
+    {
+        assert(2.to!bool == true);
+    }
+    catch (ConvException e)
+    {
+        exception = e;
+    }
+    assert(exception !is null);
+    defaultAllocator.dispose(exception);
+}
+
+/**
+ * Converts a boolean to a number. $(D_KEYWORD true) is `1`, $(D_KEYWORD false)
+ * is `0`.
+ *
+ * Params:
+ *  From = Source type.
+ *  To   = Target type.
+ *  from = Source value.
+ *
+ * Returns: `1` if $(D_PARAM from) is $(D_KEYWORD true), otherwise `0`.
+ */
+To to(To, From)(From from)
+if (is(Unqual!From == bool) && isNumeric!To && !is(Unqual!To == Unqual!From))
+{
+    return from;
+}
+
+///
+pure nothrow @safe @nogc unittest
+{
+    assert(true.to!float == 1.0);
+    assert(true.to!double == 1.0);
+    assert(true.to!ubyte == 1);
+    assert(true.to!byte == 1);
+    assert(true.to!ushort == 1);
+    assert(true.to!short == 1);
+    assert(true.to!uint == 1);
+    assert(true.to!int == 1);
+
+    assert(false.to!float == 0);
+    assert(false.to!double == 0);
+    assert(false.to!ubyte == 0);
+    assert(false.to!byte == 0);
+    assert(false.to!ushort == 0);
+    assert(false.to!short == 0);
+    assert(false.to!uint == 0);
+    assert(false.to!int == 0);
+}
+
+/**
+ * Converts a floating point number to an integral type.
+ *
+ * Params:
+ *  From = Source type.
+ *  To   = Target type.
+ *  from = Source value.
+ *
+ * Returns: Truncated $(D_PARAM from) (everything after the decimal point is
+ *          dropped).
+ *
+ * Throws: $(D_PSYMBOL ConvException) if
+ *         $(D_INLINECODE from < To.min || from > To.max).
+ */
+To to(To, From)(From from)
+if (isFloatingPoint!From
+ && isIntegral!To
+ && !is(Unqual!To == Unqual!From)
+ && !is(To == enum))
+{
+    if (from > To.max)
+    {
+        throw make!ConvException(defaultAllocator,
+                                 "Positive number overflow");
+    }
+    else if (from < To.min)
+    {
+        throw make!ConvException(defaultAllocator,
+                                 "Negative number overflow");
+    }
+    return cast(To) from;
+}
+
+///
+@nogc unittest
+{
+    assert(1.5.to!int == 1);
+    assert(2147483646.5.to!int == 2147483646);
+    assert((-2147483647.5).to!int == -2147483647);
+    assert(2147483646.5.to!uint == 2147483646);
+}
+
+private @nogc unittest
+{
+    ConvException exception;
+    try
+    {
+        assert(2147483647.5.to!int == 2147483647);
+    }
+    catch (ConvException e)
+    {
+        exception = e;
+    }
+    assert(exception !is null);
+    defaultAllocator.dispose(exception);
+}
+
+private @nogc unittest
+{
+    ConvException exception;
+    try
+    {
+        assert((-2147483648.5).to!int == -2147483648);
+    }
+    catch (ConvException e)
+    {
+        exception = e;
+    }
+    assert(exception !is null);
+    defaultAllocator.dispose(exception);
+}
+
+private @nogc unittest
+{
+    ConvException exception;
+    try
+    {
+        assert((-21474.5).to!uint == -21474);
+    }
+    catch (ConvException e)
+    {
+        exception = e;
+    }
+    assert(exception !is null);
+    defaultAllocator.dispose(exception);
+}
+
+/**
+ * Performs checked conversion from an integral type $(D_PARAM From) to an
+ * $(D_KEYWORD enum).
+ *
+ * Params:
+ *  From = Source type.
+ *  To   = Target type.
+ *  from = Source value.
+ *
+ * Returns: $(D_KEYWORD enum) value.
+ *
+ * Throws: $(D_PSYMBOL ConvException) if $(D_PARAM from) is not a member of
+ *         $(D_PSYMBOL To).
+
+ */
+To to(To, From)(From from)
+if (isIntegral!From && is(To == enum))
+{
+    foreach (m; EnumMembers!To)
+    {
+        if (from == m)
+        {
+            return m;
+        }
+    }
+    throw make!ConvException(defaultAllocator,
+                             "Value not found in enum '" ~ To.stringof ~ "'");
+}
+
+///
+@nogc unittest
+{
+    enum Test : int
+    {
+        one,
+        two,
+    }
+    static assert(is(typeof(1.to!Test) == Test));
+    assert(0.to!Test == Test.one);
+    assert(1.to!Test == Test.two);
+}
+
+private @nogc unittest
+{
+    enum Test : uint
+    {
+        one,
+        two,
+    }
+
+    ConvException exception;
+    try
+    {
+        assert(5.to!Test == Test.one);
+    }
+    catch (ConvException e)
+    {
+        exception = e;
+    }
+    assert(exception !is null);
+    defaultAllocator.dispose(exception);
+}

source/tanya/format/package.d

@@ -0,0 +1,15 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * This package contains formatting and conversion functions.
+ *
+ * Copyright: Eugene Wissner 2017.
+ * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
+ *                  Mozilla Public License, v. 2.0).
+ * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
+ */
+module tanya.format;
+
+public import tanya.format.conv;

source/tanya/math/package.d

@@ -3,6 +3,8 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 /**
+ * This package provides mathematical functions.
+ *
  * Copyright: Eugene Wissner 2016-2017.
  * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
  *                  Mozilla Public License, v. 2.0).
@@ -87,22 +89,22 @@ in
 }
 body
 {
-    size_t i = y.length;
+    size_t i;
     auto tmp1 = Integer(x, x.allocator);
     auto result = Integer(x.allocator);
+    bool firstBit;
 
-    if (x.length == 0 && i != 0)
+    if (x.size == 0 && y.size != 0)
     {
-        i = 0;
+        i = y.size;
     }
     else
     {
         result = 1;
     }
-    while (i)
+    while (i < y.size)
     {
-        --i;
-        for (ubyte mask = 0x01; mask; mask <<= 1)
+        for (uint mask = 0x01; mask != 0x10000000; mask <<= 1)
         {
             if (y.rep[i] & mask)
             {
@@ -113,6 +115,7 @@ body
             tmp1 *= tmp2;
             tmp1 %= z;
         }
+        ++i;
     }
     return result;
 }

source/tanya/math/random.d

@@ -54,17 +54,17 @@ abstract class EntropySource
     /**
      * Returns: Minimum bytes required from the entropy source.
      */
-    @property immutable(ubyte) threshold() const @safe pure nothrow;
+    @property ubyte threshold() const pure nothrow @safe @nogc;
 
     /**
      * Returns: Whether this entropy source is strong.
      */
-    @property immutable(bool) strong() const @safe pure nothrow;
+    @property bool strong() const pure nothrow @safe @nogc;
 
     /**
      * Returns: Amount of already generated entropy.
      */
-    @property ushort size() const @safe pure nothrow
+    @property ushort size() const pure nothrow @safe @nogc
     {
         return size_;
     }
@@ -74,7 +74,7 @@ abstract class EntropySource
      *  size = Amount of already generated entropy. Cannot be smaller than the
      *         already set value.
      */
-    @property void size(ushort size) @safe pure nothrow
+    @property void size(ushort size) pure nothrow @safe @nogc
     {
         size_ = size;
     }
@@ -89,12 +89,12 @@ abstract class EntropySource
      * Returns: Number of bytes that were copied to the $(D_PARAM output)
      *          or $(D_PSYMBOL Nullable!ubyte.init) on error.
      */
-    Nullable!ubyte poll(out ubyte[maxGather] output);
+    Nullable!ubyte poll(out ubyte[maxGather] output) @nogc;
 }
 
 version (linux)
 {
-    extern (C) long syscall(long number, ...) nothrow;
+    extern (C) long syscall(long number, ...) nothrow @system @nogc;
 
     /**
      * Uses getrandom system call.
@@ -104,7 +104,7 @@ version (linux)
         /**
          * Returns: Minimum bytes required from the entropy source.
          */
-        override @property immutable(ubyte) threshold() const @safe pure nothrow
+        override @property ubyte threshold() const pure nothrow @safe @nogc
         {
             return 32;
         }
@@ -112,7 +112,7 @@ version (linux)
         /**
          * Returns: Whether this entropy source is strong.
          */
-        override @property immutable(bool) strong() const @safe pure nothrow
+        override @property bool strong() const pure nothrow @safe @nogc
         {
             return true;
         }
@@ -127,7 +127,7 @@ version (linux)
          * Returns: Number of bytes that were copied to the $(D_PARAM output)
          *          or $(D_PSYMBOL Nullable!ubyte.init) on error.
          */
-        override Nullable!ubyte poll(out ubyte[maxGather] output) nothrow
+        override Nullable!ubyte poll(out ubyte[maxGather] output) nothrow @nogc
         out (length)
         {
             assert(length <= maxGather);
@@ -145,6 +145,18 @@ version (linux)
             return ret;
         }
     }
+
+    version (X86_64)
+    {
+        private unittest
+        {
+            auto entropy = defaultAllocator.make!Entropy();
+            ubyte[blockSize] output;
+            output = entropy.random;
+
+            defaultAllocator.dispose(entropy);
+        }
+    }
 }
 
 /**
@@ -177,7 +189,8 @@ class Entropy
      *  allocator  = Allocator to allocate entropy sources available on the
      *               system.
      */
-    this(size_t maxSources = 20, shared Allocator allocator = defaultAllocator)
+    this(const size_t maxSources = 20,
+         shared Allocator allocator = defaultAllocator) @nogc
     in
     {
         assert(maxSources > 0 && maxSources <= ubyte.max);
@@ -196,7 +209,7 @@ class Entropy
     /**
      * Returns: Amount of the registered entropy sources.
      */
-    @property ubyte sourceCount() const @safe pure nothrow
+    @property ubyte sourceCount() const pure nothrow @safe @nogc
     {
         return sourceCount_;
     }
@@ -212,7 +225,7 @@ class Entropy
      * See_Also:
      *  $(D_PSYMBOL EntropySource)
      */
-    Entropy opOpAssign(string Op)(EntropySource source) @safe pure nothrow
+    Entropy opOpAssign(string Op)(EntropySource source) pure nothrow @safe @nogc
         if (Op == "~")
     in
     {
@@ -230,7 +243,7 @@ class Entropy
      * Throws: $(D_PSYMBOL EntropyException) if no strong entropy source was
      *         registered or it failed.
      */
-    @property ubyte[blockSize] random()
+    @property ubyte[blockSize] random() @nogc
     in
     {
         assert(sourceCount_ > 0, "No entropy sources defined.");
@@ -301,13 +314,13 @@ class Entropy
      */
     protected void update(in ubyte sourceId,
                           ref ubyte[maxGather] data,
-                          ubyte length) @safe pure nothrow
+                          ubyte length) pure nothrow @safe @nogc
     {
         ubyte[2] header;
 
         if (length > blockSize)
         {
-            data[0..64] = sha512Of(data);
+            data[0 .. 64] = sha512Of(data);
             length = blockSize;
         }
 
@@ -315,6 +328,6 @@ class Entropy
         header[1] = length;
 
         accumulator.put(header);
-        accumulator.put(data[0..length]);
+        accumulator.put(data[0 .. length]);
     }
 }

source/tanya/memory/allocator.d

@@ -3,6 +3,11 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 /**
+ * This module contains the interface for implementing custom allocators.
+ *
+ * Allocators are classes encapsulating memory allocation strategy. This allows
+ * to decouple memory management from the algorithms and the data. 
+ *
  * Copyright: Eugene Wissner 2016-2017.
  * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
  *                  Mozilla Public License, v. 2.0).
@@ -28,7 +33,7 @@ interface Allocator
      *
      * Returns: Pointer to the new allocated memory.
      */
-    void[] allocate(in size_t size) shared nothrow @nogc;
+    void[] allocate(const size_t size) shared pure nothrow @nogc;
 
     /**
      * Deallocates a memory block.
@@ -38,7 +43,7 @@ interface Allocator
      *
      * Returns: Whether the deallocation was successful.
      */
-    bool deallocate(void[] p) shared nothrow @nogc;
+    bool deallocate(void[] p) shared pure nothrow @nogc;
 
     /**
      * Increases or decreases the size of a memory block.
@@ -49,7 +54,7 @@ interface Allocator
      *
      * Returns: Pointer to the allocated memory.
      */
-    bool reallocate(ref void[] p, in size_t size) shared nothrow @nogc;
+    bool reallocate(ref void[] p, const size_t size) shared pure nothrow @nogc;
 
     /**
      * Reallocates a memory block in place if possible or returns
@@ -63,5 +68,12 @@ interface Allocator
      *
      * Returns: $(D_KEYWORD true) if successful, $(D_KEYWORD false) otherwise.
      */
-    bool reallocateInPlace(ref void[] p, in size_t size) shared nothrow @nogc;
+    bool reallocateInPlace(ref void[] p, const size_t size)
+    shared pure nothrow @nogc;
+}
+
+package template GetPureInstance(T : Allocator)
+{
+    alias GetPureInstance = shared(T) function()
+                            pure nothrow @nogc;
 }

source/tanya/memory/mallocator.d

@@ -3,6 +3,8 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 /**
+ * Allocator based on $(D_PSYMBOL malloc), $(D_PSYMBOL realloc) and $(D_PSYMBOL free).
+ *
  * Copyright: Eugene Wissner 2017.
  * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
  *                  Mozilla Public License, v. 2.0).
@@ -11,14 +13,21 @@
 module tanya.memory.mallocator;
 
 import core.stdc.stdlib;
-import std.algorithm.comparison;
 import tanya.memory.allocator;
 
 /**
- * Wrapper for malloc/realloc/free from the C standard library.
+ * Wrapper for $(D_PSYMBOL malloc)/$(D_PSYMBOL realloc)/$(D_PSYMBOL free) from
+ * the C standard library.
  */
 final class Mallocator : Allocator
 {
+    private alias MallocType = extern (C) void* function(size_t)
+                               pure nothrow @system @nogc;
+    private alias FreeType = extern (C) void function(void*)
+                             pure nothrow @system @nogc;
+    private alias ReallocType = extern (C) void* function(void*, size_t)
+                                pure nothrow @system @nogc;
+
     /**
      * Allocates $(D_PARAM size) bytes of memory.
      *
@@ -27,13 +36,13 @@ final class Mallocator : Allocator
      *
      * Returns: The pointer to the new allocated memory.
      */
-    void[] allocate(in size_t size) shared nothrow @nogc
+    void[] allocate(const size_t size) shared pure nothrow @nogc
     {
-        if (!size)
+        if (size == 0)
         {
             return null;
         }
-        auto p = malloc(size + psize);
+        auto p = (cast(MallocType) &malloc)(size + psize);
 
         return p is null ? null : p[psize .. psize + size];
     }
@@ -42,10 +51,11 @@ final class Mallocator : Allocator
     @nogc nothrow unittest
     {
         auto p = Mallocator.instance.allocate(20);
-
         assert(p.length == 20);
-
         Mallocator.instance.deallocate(p);
+
+        p = Mallocator.instance.allocate(0);
+        assert(p.length == 0);
     }
 
     /**
@@ -56,11 +66,11 @@ final class Mallocator : Allocator
      *
      * Returns: Whether the deallocation was successful.
      */
-    bool deallocate(void[] p) shared nothrow @nogc
+    bool deallocate(void[] p) shared pure nothrow @nogc
     {
         if (p !is null)
         {
-            free(p.ptr - psize);
+            (cast(FreeType) &free)(p.ptr - psize);
         }
         return true;
     }
@@ -84,11 +94,19 @@ final class Mallocator : Allocator
      *
      * Returns: $(D_KEYWORD false).
      */
-    bool reallocateInPlace(ref void[] p, const size_t size) shared nothrow @nogc
+    bool reallocateInPlace(ref void[] p, const size_t size)
+    shared pure nothrow @nogc
     {
         return false;
     }
 
+    ///
+    @nogc nothrow unittest
+    {
+        void[] p;
+        assert(!Mallocator.instance.reallocateInPlace(p, 8));
+    }
+
     /**
      * Increases or decreases the size of a memory block.
      *
@@ -98,7 +116,7 @@ final class Mallocator : Allocator
      *
      * Returns: Whether the reallocation was successful.
      */
-    bool reallocate(ref void[] p, const size_t size) shared nothrow @nogc
+    bool reallocate(ref void[] p, const size_t size) shared pure nothrow @nogc
     {
         if (size == 0)
         {
@@ -115,7 +133,7 @@ final class Mallocator : Allocator
         }
         else
         {
-            auto r = realloc(p.ptr - psize, size + psize);
+            auto r = (cast(ReallocType) &realloc)(p.ptr - psize, size + psize);
 
             if (r !is null)
             {
@@ -144,24 +162,34 @@ final class Mallocator : Allocator
         assert(p is null);
     }
 
+    // Fails with false.
+    private @nogc nothrow unittest
+    {
+        void[] p = Mallocator.instance.allocate(20);
+        void[] oldP = p;
+        assert(!Mallocator.instance.reallocate(p, size_t.max - Mallocator.psize * 2));
+        assert(oldP is p);
+        Mallocator.instance.deallocate(p);
+    }
+
     /**
      * Returns: The alignment offered.
      */
     @property uint alignment() shared const pure nothrow @safe @nogc
     {
-        return cast(uint) max(double.alignof, real.alignof);
+        return (void*).alignof;
     }
 
-    /**
-     * Static allocator instance and initializer.
-     *
-     * Returns: The global $(D_PSYMBOL Allocator) instance.
-     */
-    static @property ref shared(Mallocator) instance() @nogc nothrow
+    private nothrow @nogc unittest
+    {
+        assert(Mallocator.instance.alignment == (void*).alignof);
+    }
+
+    static private shared(Mallocator) instantiate() nothrow @nogc
     {
         if (instance_ is null)
         {
-            immutable size = __traits(classInstanceSize, Mallocator) + psize;
+            const size = __traits(classInstanceSize, Mallocator) + psize;
             void* p = malloc(size);
 
             if (p !is null)
@@ -173,13 +201,23 @@ final class Mallocator : Allocator
         return instance_;
     }
 
+    /**
+     * Static allocator instance and initializer.
+     *
+     * Returns: The global $(D_PSYMBOL Allocator) instance.
+     */
+    static @property shared(Mallocator) instance() pure nothrow @nogc
+    {
+        return (cast(GetPureInstance!Mallocator) &instantiate)();
+    }
+
     ///
     @nogc nothrow unittest
     {
         assert(instance is instance);
     }
 
-    private enum psize = 8;
+    private enum ushort psize = 8;
 
     private shared static Mallocator instance_;
 }

source/tanya/memory/mmappool.d

@@ -3,6 +3,8 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 /**
+ * Native allocator for Posix and Windows.
+ *
  * Copyright: Eugene Wissner 2016-2017.
  * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
  *                  Mozilla Public License, v. 2.0).
@@ -16,14 +18,63 @@ import tanya.memory.allocator;
 
 version (Posix)
 {
-	import core.stdc.errno;
-	import core.sys.posix.sys.mman;
+    import core.sys.posix.sys.mman : PROT_READ, PROT_WRITE, MAP_PRIVATE,
+                                     MAP_ANON, MAP_FAILED;
     import core.sys.posix.unistd;
+
+    extern (C)
+    private void* mmap(void* addr,
+                       size_t len,
+                       int prot,
+                       int flags,
+                       int fd,
+                       off_t offset) pure nothrow @system @nogc;
+
+    extern (C)
+    private int munmap(void* addr, size_t len) pure nothrow @system @nogc;
+
+    private void* mapMemory(const size_t len) pure nothrow @system @nogc
+    {
+        void* p = mmap(null,
+                       len,
+                       PROT_READ | PROT_WRITE,
+                       MAP_PRIVATE | MAP_ANON,
+                       -1,
+                       0);
+        return p is MAP_FAILED ? null : p;
+    }
+
+    private bool unmapMemory(shared void* addr, const size_t len)
+    pure nothrow @system @nogc
+    {
+        return munmap(cast(void*) addr, len) == 0;
+    }
 }
 else version (Windows)
 {
-	import core.sys.windows.winbase;
-	import core.sys.windows.windows;
+    import core.sys.windows.winbase : GetSystemInfo, SYSTEM_INFO;
+
+    extern (Windows)
+    private void* VirtualAlloc(void*, size_t, uint, uint)
+    pure nothrow @system @nogc;
+
+    extern (Windows)
+    private int VirtualFree(void* addr, size_t len, uint)
+    pure nothrow @system @nogc;
+
+    private void* mapMemory(const size_t len) pure nothrow @system @nogc
+    {
+        return VirtualAlloc(null,
+                            len,
+                            0x00001000, // MEM_COMMIT
+                            0x04); // PAGE_READWRITE
+    }
+
+    private bool unmapMemory(shared void* addr, const size_t len)
+    pure nothrow @system @nogc
+    {
+        return VirtualFree(cast(void*) addr, 0, 0x8000) == 0;
+    }
 }
 
 /**
@@ -50,7 +101,9 @@ else version (Windows)
  */
 final class MmapPool : Allocator
 {
-	invariant
+    version (none)
+    {
+        pure nothrow @nogc invariant
         {
             for (auto r = &head; *r !is null; r = &((*r).next))
             {
@@ -64,6 +117,7 @@ final class MmapPool : Allocator
                 while ((block = block.next) !is null);
             }
         }
+    }
 
     /**
      * Allocates $(D_PARAM size) bytes of memory.
@@ -73,13 +127,17 @@ final class MmapPool : Allocator
      *
      * Returns: Pointer to the new allocated memory.
      */
-	void[] allocate(in size_t size) shared nothrow @nogc
+    void[] allocate(const size_t size) shared pure nothrow @nogc
     {
-		if (!size)
+        if (size == 0)
+        {
+            return null;
+        }
+        const dataSize = addAlignment(size);
+        if (dataSize < size)
         {
             return null;
         }
-		immutable dataSize = addAlignment(size);
 
         void* data = findBlock(dataSize);
         if (data is null)
@@ -94,13 +152,32 @@ final class MmapPool : Allocator
     nothrow unittest
     {
         auto p = MmapPool.instance.allocate(20);
-
         assert(p);
-
         MmapPool.instance.deallocate(p);
+
+        p = MmapPool.instance.allocate(0);
+        assert(p.length == 0);
     }
 
-	/**
+    // Issue 245: https://issues.caraus.io/issues/245.
+    private @nogc unittest
+    {
+        // allocate() check.
+        size_t tooMuchMemory = size_t.max
+                             - MmapPool.alignment_
+                             - BlockEntry.sizeof * 2
+                             - RegionEntry.sizeof
+                             - MmapPool.instance.pageSize;
+        assert(MmapPool.instance.allocate(tooMuchMemory) is null);
+
+        assert(MmapPool.instance.allocate(size_t.max) is null);
+
+        // initializeRegion() check.
+        tooMuchMemory = size_t.max - MmapPool.alignment_;
+        assert(MmapPool.instance.allocate(tooMuchMemory) is null);
+    }
+
+    /*
      * Search for a block large enough to keep $(D_PARAM size) and split it
      * into two blocks if the block is too large.
      *
@@ -109,7 +186,7 @@ final class MmapPool : Allocator
      *
      * Returns: Data the block points to or $(D_KEYWORD null).
      */
-	private void* findBlock(in ref size_t size) shared nothrow @nogc
+    private void* findBlock(const ref size_t size) shared pure nothrow @nogc
     {
         Block block1;
         RegionLoop: for (auto r = head; r !is null; r = r.next)
@@ -169,7 +246,7 @@ final class MmapPool : Allocator
      *
      * Returns: Whether the deallocation was successful.
      */
-	bool deallocate(void[] p) shared nothrow @nogc
+    bool deallocate(void[] p) shared pure nothrow @nogc
     {
         if (p.ptr is null)
         {
@@ -191,14 +268,7 @@ final class MmapPool : Allocator
             {
                 block.region.next.prev = block.region.prev;
             }
-			version (Posix)
-			{
-				return munmap(cast(void*) block.region, block.region.size) == 0;
-			}
-			version (Windows)
-			{
-				return VirtualFree(cast(void*) block.region, 0, MEM_RELEASE) == 0;
-			}
+            return unmapMemory(block.region, block.region.size);
         }
         // Merge blocks if neigbours are free.
         if (block.next !is null && block.next.free)
@@ -242,7 +312,8 @@ final class MmapPool : Allocator
      *
      * Returns: $(D_KEYWORD true) if successful, $(D_KEYWORD false) otherwise.
      */
-	bool reallocateInPlace(ref void[] p, in size_t size) shared nothrow @nogc
+    bool reallocateInPlace(ref void[] p, const size_t size)
+    shared pure nothrow @nogc
     {
         if (p is null || size == 0)
         {
@@ -258,19 +329,25 @@ final class MmapPool : Allocator
 
         if (block1.size >= size)
         {
-			// Enough space in the current block. Can happen because of the alignment.
+            // Enough space in the current block.
             p = p.ptr[0 .. size];
             return true;
         }
-		immutable dataSize = addAlignment(size);
-		immutable delta = dataSize - addAlignment(p.length);
+        const dataSize = addAlignment(size);
+        const pAlignment = addAlignment(p.length);
+        assert(pAlignment >= p.length, "Invalid memory chunk length");
+        const delta = dataSize - pAlignment;
 
         if (block1.next is null
          || !block1.next.free
+         || dataSize < size
          || block1.next.size + BlockEntry.sizeof < delta)
         {
-			// It is the last block in the region or the next block is too small or not
-			// free.
+            /* * It is the last block in the region
+             * * The next block is too small
+             * * The next block isn't free
+             * * Requested size is too large
+             */
             return false;
         }
         if (block1.next.size >= delta + alignment_)
@@ -333,7 +410,7 @@ final class MmapPool : Allocator
      *
      * Returns: Whether the reallocation was successful.
      */
-	bool reallocate(ref void[] p, in size_t size) shared nothrow @nogc
+    bool reallocate(ref void[] p, const size_t size) shared pure nothrow @nogc
     {
         if (size == 0)
         {
@@ -394,19 +471,14 @@ final class MmapPool : Allocator
         MmapPool.instance.deallocate(p);
     }
 
-	/**
-	 * Static allocator instance and initializer.
-	 *
-	 * Returns: Global $(D_PSYMBOL MmapPool) instance.
-	 */
-	static @property ref shared(MmapPool) instance() nothrow @nogc
+    static private shared(MmapPool) instantiate() nothrow @nogc
     {
         if (instance_ is null)
         {
             // Get system dependend page size.
             version (Posix)
             {
-				pageSize = sysconf(_SC_PAGE_SIZE);
+                size_t pageSize = sysconf(_SC_PAGE_SIZE);
                 if (pageSize < 65536)
                 {
                     pageSize = pageSize * 65536 / pageSize;
@@ -416,23 +488,35 @@ final class MmapPool : Allocator
             {
                 SYSTEM_INFO si;
                 GetSystemInfo(&si);
-				pageSize = si.dwPageSize;
+                size_t pageSize = si.dwPageSize;
             }
 
-			immutable instanceSize = addAlignment(__traits(classInstanceSize, MmapPool));
+            const instanceSize = addAlignment(__traits(classInstanceSize,
+                                              MmapPool));
 
             Region head; // Will become soon our region list head
-			void* data = initializeRegion(instanceSize, head);
+            void* data = initializeRegion(instanceSize, head, pageSize);
             if (data !is null)
             {
                 memcpy(data, typeid(MmapPool).initializer.ptr, instanceSize);
                 instance_ = cast(shared MmapPool) data;
                 instance_.head = head;
+                instance_.pageSize = pageSize;
             }
         }
         return instance_;
     }
 
+    /**
+     * Static allocator instance and initializer.
+     *
+     * Returns: Global $(D_PSYMBOL MmapPool) instance.
+     */
+    static @property shared(MmapPool) instance() pure nothrow @nogc
+    {
+        return (cast(GetPureInstance!MmapPool) &instantiate)();
+    }
+
     ///
     nothrow unittest
     {
@@ -448,35 +532,22 @@ final class MmapPool : Allocator
      *
      * Returns: A pointer to the data.
      */
-	private static void* initializeRegion(size_t size, ref Region head)
-	nothrow @nogc
+    private static void* initializeRegion(const size_t size,
+                                          ref Region head,
+                                          const size_t pageSize)
+    pure nothrow @nogc
     {
-		immutable regionSize = calculateRegionSize(size);
-		
-		version (Posix)
-		{
-			void* p = mmap(null,
-			               regionSize,
-			               PROT_READ | PROT_WRITE,
-			               MAP_PRIVATE | MAP_ANON,
-			               -1,
-			               0);
-			if (p is MAP_FAILED)
+        const regionSize = calculateRegionSize(size, pageSize);
+        if (regionSize < size)
         {
             return null;
         }
-		}
-		else version (Windows)
-		{
-			void* p = VirtualAlloc(null,
-			                       regionSize,
-			                       MEM_COMMIT,
-			                       PAGE_READWRITE);
+
+        void* p = mapMemory(regionSize);
         if (p is null)
         {
             return null;
         }
-		}
 
         Region region = cast(Region) p;
         region.blocks = 1;
@@ -513,9 +584,9 @@ final class MmapPool : Allocator
         return data;
     }
 
-	private void* initializeRegion(size_t size) shared nothrow @nogc
+    private void* initializeRegion(const size_t size) shared pure nothrow @nogc
     {
-		return initializeRegion(size, head);
+        return initializeRegion(size, this.head, this.pageSize);
     }
 
     /*
@@ -524,13 +595,7 @@ final class MmapPool : Allocator
      *
      * Returns: Aligned size of $(D_PARAM x).
      */
-	private static immutable(size_t) addAlignment(size_t x)
-	pure nothrow @safe @nogc
-	out (result)
-	{
-		assert(result > 0);
-	}
-	body
+    private static size_t addAlignment(const size_t x) pure nothrow @safe @nogc
     {
         return (x - 1) / alignment_ * alignment_ + alignment_;
     }
@@ -538,19 +603,16 @@ final class MmapPool : Allocator
     /*
      * Params:
      *  x        = Required space.
+     *  pageSize = Page size.
      *
      * Returns: Minimum region size (a multiple of $(D_PSYMBOL pageSize)).
      */
-	private static immutable(size_t) calculateRegionSize(size_t x)
-	nothrow @safe @nogc
-	out (result)
+    private static size_t calculateRegionSize(ref const size_t x,
+                                              ref const size_t pageSize)
+    pure nothrow @safe @nogc
     {
-		assert(result > 0);
-	}
-	body
-	{
-		x += RegionEntry.sizeof + BlockEntry.sizeof * 2;
-		return x / pageSize * pageSize + pageSize;
+        return (x + RegionEntry.sizeof + BlockEntry.sizeof * 2)
+             / pageSize * pageSize + pageSize;
     }
 
     /**
@@ -560,10 +622,16 @@ final class MmapPool : Allocator
     {
         return alignment_;
     }
-	private enum alignment_ = 8;
+
+    private nothrow @nogc unittest
+    {
+        assert(MmapPool.instance.alignment == MmapPool.alignment_);
+    }
+
+    private enum uint alignment_ = 8;
 
     private shared static MmapPool instance_;
-	private shared static size_t pageSize;
+    private shared size_t pageSize;
 
     private shared struct RegionEntry
     {
@@ -588,7 +656,7 @@ final class MmapPool : Allocator
 
 // A lot of allocations/deallocations, but it is the minimum caused a
 // segmentation fault because MmapPool reallocateInPlace moves a block wrong.
-unittest
+private @nogc unittest
 {
     auto a = MmapPool.instance.allocate(16);
     auto d = MmapPool.instance.allocate(16);

source/tanya/memory/package.d

@@ -3,6 +3,8 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 /**
+ * Dynamic memory management.
+ *
  * Copyright: Eugene Wissner 2016-2017.
  * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
  *                  Mozilla Public License, v. 2.0).
@@ -11,9 +13,13 @@
 module tanya.memory;
 
 import core.exception;
-public import std.experimental.allocator : make;
+import std.algorithm.iteration;
+import std.algorithm.mutation;
+import std.conv;
+import std.range;
 import std.traits;
 public import tanya.memory.allocator;
+import tanya.memory.mmappool;
 
 /**
  * The mixin generates common methods for classes and structs using
@@ -32,7 +38,7 @@ mixin template DefaultAllocator()
      *
      * Precondition: $(D_INLINECODE allocator_ !is null)
      */
-    this(shared Allocator allocator)
+    this(shared Allocator allocator) pure nothrow @safe @nogc
     in
     {
         assert(allocator !is null);
@@ -50,7 +56,7 @@ mixin template DefaultAllocator()
      *
      * Postcondition: $(D_INLINECODE allocator !is null)
      */
-    protected @property shared(Allocator) allocator() nothrow @safe @nogc
+    protected @property shared(Allocator) allocator() pure nothrow @safe @nogc
     out (allocator)
     {
         assert(allocator !is null);
@@ -65,7 +71,7 @@ mixin template DefaultAllocator()
     }
 
     /// Ditto.
-    @property shared(Allocator) allocator() const nothrow @trusted @nogc
+    @property shared(Allocator) allocator() const pure nothrow @trusted @nogc
     out (allocator)
     {
         assert(allocator !is null);
@@ -81,26 +87,44 @@ mixin template DefaultAllocator()
 }
 
 // From druntime
-private extern (C) void _d_monitordelete(Object h, bool det) nothrow @nogc;
+extern (C)
+private void _d_monitordelete(Object h, bool det) pure nothrow @nogc;
 
 shared Allocator allocator;
 
-shared static this() nothrow @trusted @nogc
+shared static this() nothrow @nogc
 {
-    import tanya.memory.mallocator;
-    allocator = Mallocator.instance;
+    allocator = MmapPool.instance;
 }
 
-@property ref shared(Allocator) defaultAllocator() nothrow @safe @nogc
+private shared(Allocator) getAllocatorInstance() nothrow @nogc
+{
+    return allocator;
+}
+
+/**
+ * Returns: Default allocator.
+ *
+ * Postcondition: $(D_INLINECODE allocator !is null).
+ */
+@property shared(Allocator) defaultAllocator() pure nothrow @trusted @nogc
 out (allocator)
 {
     assert(allocator !is null);
 }
 body
 {
-    return allocator;
+    return (cast(GetPureInstance!Allocator) &getAllocatorInstance)();
 }
 
+/**
+ * Sets the default allocator.
+ *
+ * Params:
+ *  allocator = $(D_PSYMBOL Allocator) instance.
+ *
+ * Precondition: $(D_INLINECODE allocator !is null).
+ */
 @property void defaultAllocator(shared(Allocator) allocator) nothrow @safe @nogc
 in
 {
@@ -111,6 +135,17 @@ body
     .allocator = allocator;
 }
 
+private nothrow @nogc unittest
+{
+    import tanya.memory.mallocator;
+
+    auto oldAllocator = defaultAllocator;
+    defaultAllocator = Mallocator.instance;
+    assert(defaultAllocator is Mallocator.instance);
+
+    defaultAllocator = oldAllocator;
+}
+
 /**
  * Returns the size in bytes of the state that needs to be allocated to hold an
  * object of type $(D_PARAM T).
@@ -202,40 +237,32 @@ private unittest
     assert(p is null);
 }
 
-/**
- * Destroys and deallocates $(D_PARAM p) of type $(D_PARAM T).
- * It is assumed the respective entities had been allocated with the same
- * allocator.
- *
- * Params:
- *  T         = Type of $(D_PARAM p).
- *  allocator = Allocator the $(D_PARAM p) was allocated with.
- *  p         = Object or array to be destroyed.
+/*
+ * Destroys the object.
+ * Returns the memory should be freed.
  */
-void dispose(T)(shared Allocator allocator, auto ref T* p)
+package(tanya) void[] finalize(T)(ref T* p)
 {
     static if (hasElaborateDestructor!T)
     {
         destroy(*p);
     }
-    () @trusted { allocator.deallocate((cast(void*) p)[0 .. T.sizeof]); }();
-    p = null;
+    return (cast(void*) p)[0 .. T.sizeof];
 }
 
-/// Ditto.
-void dispose(T)(shared Allocator allocator, auto ref T p)
+package(tanya) void[] finalize(T)(ref T p)
     if (is(T == class) || is(T == interface))
 {
     if (p is null)
     {
-        return;
+        return null;
     }
     static if (is(T == interface))
     {
         version(Windows)
         {
             import core.sys.windows.unknwn : IUnknown;
-            static assert(!is(T: IUnknown), "COM interfaces can't be destroyed in "
+            static assert(!is(T : IUnknown), "COM interfaces can't be destroyed in "
                                            ~ __PRETTY_FUNCTION__);
         }
         auto ob = cast(Object) p;
@@ -244,19 +271,13 @@ void dispose(T)(shared Allocator allocator, auto ref T p)
     {
         alias ob = p;
     }
-    auto ptr = cast(void *) ob;
-
+    auto ptr = cast(void*) ob;
     auto support = ptr[0 .. typeid(ob).initializer.length];
-    scope (success)
-    {
-        () @trusted { allocator.deallocate(support); }();
-        p = null;
-    }
 
     auto ppv = cast(void**) ptr;
     if (!*ppv)
     {
-        return;
+        return null;
     }
     auto pc = cast(ClassInfo*) *ppv;
     scope (exit)
@@ -271,7 +292,8 @@ void dispose(T)(shared Allocator allocator, auto ref T p)
         // shouldn't throw and if it does, it is an error anyway.
         if (c.destructor)
         {
-            (cast(void function (Object) nothrow @safe @nogc) c.destructor)(ob);
+            alias DtorType = void function(Object) pure nothrow @safe @nogc;
+            (cast(DtorType) c.destructor)(ob);
         }
     }
     while ((c = c.base) !is null);
@@ -280,21 +302,35 @@ void dispose(T)(shared Allocator allocator, auto ref T p)
     {
         _d_monitordelete(cast(Object) ptr, true);
     }
+    return support;
 }
 
-/// Ditto.
-void dispose(T)(shared Allocator allocator, auto ref T[] p)
+package(tanya) void[] finalize(T)(ref T[] p)
 {
     static if (hasElaborateDestructor!(typeof(p[0])))
     {
-        import std.algorithm.iteration;
-        p.each!(e => destroy(e));
+        p.each!((ref e) => destroy(e));
     }
-    () @trusted { allocator.deallocate(p); }();
+    return p;
+}
+
+/**
+ * Destroys and deallocates $(D_PARAM p) of type $(D_PARAM T).
+ * It is assumed the respective entities had been allocated with the same
+ * allocator.
+ *
+ * Params:
+ *  T         = Type of $(D_PARAM p).
+ *  allocator = Allocator the $(D_PARAM p) was allocated with.
+ *  p         = Object or array to be destroyed.
+ */
+void dispose(T)(shared Allocator allocator, auto ref T p)
+{
+    () @trusted { allocator.deallocate(finalize(p)); }();
     p = null;
 }
 
-unittest
+private unittest
 {
     struct S
     {
@@ -306,3 +342,148 @@ unittest
 
     defaultAllocator.dispose(p);
 }
+
+// Works with interfaces.
+private pure unittest
+{
+    interface I
+    {
+    }
+    class C : I
+    {
+    }
+    auto c = defaultAllocator.make!C();
+    I i = c;
+
+    defaultAllocator.dispose(i);
+    defaultAllocator.dispose(i);
+}
+
+/**
+ * Constructs a new class instance of type $(D_PARAM T) using $(D_PARAM args)
+ * as the parameter list for the constructor of $(D_PARAM T).
+ *
+ * Params:
+ *  T         = Class type.
+ *  A         = Types of the arguments to the constructor of $(D_PARAM T).
+ *  allocator = Allocator.
+ *  args      = Constructor arguments of $(D_PARAM T).
+ * 
+ * Returns: Newly created $(D_PSYMBOL T).
+ *
+ * Precondition: $(D_INLINECODE allocator !is null)
+ */
+T make(T, A...)(shared Allocator allocator, auto ref A args)
+if (is(T == class))
+in
+{
+    assert(allocator !is null);
+}
+body
+{
+    T ret;
+    const size = stateSize!T;
+
+    auto mem = (() @trusted => allocator.allocate(size))();
+    if (mem is null)
+    {
+        onOutOfMemoryError();
+    }
+    scope (failure)
+    {
+        () @trusted { allocator.deallocate(mem); }();
+    }
+
+    ret = emplace!T(mem[0 .. size], args);
+
+    return ret;
+}
+
+/**
+ * Constructs a value object of type $(D_PARAM T) using $(D_PARAM args)
+ * as the parameter list for the constructor of $(D_PARAM T) and returns a
+ * pointer to the new object.
+ *
+ * Params:
+ *  T         = Object type.
+ *  A         = Types of the arguments to the constructor of $(D_PARAM T).
+ *  allocator = Allocator.
+ *  args      = Constructor arguments of $(D_PARAM T).
+ * 
+ * Returns: Pointer to the created object.
+ *
+ * Precondition: $(D_INLINECODE allocator !is null)
+ */
+T* make(T, A...)(shared Allocator allocator, auto ref A args)
+if (!is(T == interface)
+ && !is(T == class)
+ && !isAssociativeArray!T
+ && !isArray!T)
+in
+{
+    assert(allocator !is null);
+}
+body
+{
+    typeof(return) ret;
+    const size = stateSize!T;
+
+    auto mem = (() @trusted => allocator.allocate(size))();
+    if (mem is null)
+    {
+        onOutOfMemoryError();
+    }
+    scope (failure)
+    {
+        () @trusted { allocator.deallocate(mem); }();
+    }
+
+    auto ptr = (() @trusted => (cast(T*) mem[0 .. size].ptr))();
+    ret = emplace!T(ptr, args);
+
+    return ret;
+}
+
+///
+unittest
+{
+    int* i = defaultAllocator.make!int(5);
+    assert(*i == 5);
+    defaultAllocator.dispose(i);
+}
+
+/**
+ * Constructs a new array with $(D_PARAM size) elements.
+ *
+ * Params:
+ *  T         = Array type.
+ *  allocator = Allocator.
+ *  size      = Array size.
+ *
+ * Returns: Newly created array.
+ *
+ * Precondition: $(D_INLINECODE allocator !is null
+ *                           && n <= size_t.max / ElementType!T.sizeof)
+ */
+T make(T)(shared Allocator allocator, const size_t n)
+if (isArray!T)
+in
+{
+    assert(allocator !is null);
+    assert(n <= size_t.max / ElementType!T.sizeof);
+}
+body
+{
+    auto ret = allocator.resize!(ElementType!T)(null, n);
+    ret.uninitializedFill(ElementType!T.init);
+    return ret;
+}
+
+///
+unittest
+{
+    int[] i = defaultAllocator.make!(int[])(2);
+    assert(i.length == 2);
+    assert(i[0] == int.init && i[1] == int.init);
+    defaultAllocator.dispose(i);
+}

source/tanya/memory/smartref.d

@@ -0,0 +1,923 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Smart pointers.
+ *
+ * A smart pointer is an object that wraps a raw pointer or a reference
+ * (class, array) to manage its lifetime.
+ *
+ * Copyright: Eugene Wissner 2016-2017.
+ * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
+ *                  Mozilla Public License, v. 2.0).
+ * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
+ */
+module tanya.memory.smartref;
+
+import core.exception;
+import std.algorithm.comparison;
+import std.algorithm.mutation;
+import std.conv;
+import std.range;
+import std.traits;
+import tanya.memory;
+
+private template Payload(T)
+{
+    static if (is(T == class) || is(T == interface) || isArray!T)
+    {
+        alias Payload = T;
+    }
+    else
+    {
+        alias Payload = T*;
+    }
+}
+
+private final class RefCountedStore(T)
+{
+    T payload;
+    size_t counter = 1;
+
+    size_t opUnary(string op)()
+    if (op == "--" || op == "++")
+    in
+    {
+        assert(this.counter > 0);
+    }
+    body
+    {
+        mixin("return " ~ op ~ "counter;");
+    }
+
+    int opCmp(const size_t counter)
+    {
+        if (this.counter > counter)
+        {
+            return 1;
+        }
+        else if (this.counter < counter)
+        {
+            return -1;
+        }
+        else
+        {
+            return 0;
+        }
+    }
+}
+
+private void separateDeleter(T)(RefCountedStore!T storage,
+                                shared Allocator allocator)
+{
+    allocator.dispose(storage.payload);
+    allocator.dispose(storage);
+}
+
+private void unifiedDeleter(T)(RefCountedStore!T storage,
+                               shared Allocator allocator)
+{
+    auto ptr1 = finalize(storage);
+    auto ptr2 = finalize(storage.payload);
+    allocator.deallocate(ptr1.ptr[0 .. ptr1.length + ptr2.length]);
+}
+
+/**
+ * Reference-counted object containing a $(D_PARAM T) value as payload.
+ * $(D_PSYMBOL RefCounted) keeps track of all references of an object, and
+ * when the reference count goes down to zero, frees the underlying store.
+ *
+ * Params:
+ *  T = Type of the reference-counted value.
+ */
+struct RefCounted(T)
+{
+    private alias Storage = RefCountedStore!(Payload!T);
+
+    private Storage storage;
+    private void function(Storage storage,
+                          shared Allocator allocator) @nogc deleter;
+
+    invariant
+    {
+        assert(this.storage is null || this.allocator_ !is null);
+        assert(this.storage is null || this.deleter !is null);
+    }
+
+    /**
+     * Takes ownership over $(D_PARAM value), setting the counter to 1.
+     * $(D_PARAM value) may be a pointer, an object or a dynamic array.
+     *
+     * Params:
+     *  value     = Value whose ownership is taken over.
+     *  allocator = Allocator used to destroy the $(D_PARAM value) and to
+     *              allocate/deallocate internal storage.
+     *
+     * Precondition: $(D_INLINECODE allocator !is null)
+     */
+    this(Payload!T value, shared Allocator allocator = defaultAllocator)
+    {
+        this(allocator);
+        this.storage = allocator.make!Storage();
+        this.deleter = &separateDeleter!(Payload!T);
+
+        this.storage.payload = value;
+    }
+
+    /// Ditto.
+    this(shared Allocator allocator)
+    in
+    {
+        assert(allocator !is null);
+    }
+    body
+    {
+        this.allocator_ = allocator;
+    }
+
+    /**
+     * Increases the reference counter by one.
+     */
+    this(this)
+    {
+        if (count != 0)
+        {
+            ++this.storage;
+        }
+    }
+
+    /**
+     * Decreases the reference counter by one.
+     *
+     * If the counter reaches 0, destroys the owned object.
+     */
+    ~this()
+    {
+        if (this.storage !is null && !(this.storage > 0 && --this.storage))
+        {
+            deleter(this.storage, allocator);
+        }
+    }
+
+    /**
+     * Takes ownership over $(D_PARAM rhs). Initializes this
+     * $(D_PSYMBOL RefCounted) if needed.
+     *
+     * If it is the last reference of the previously owned object,
+     * it will be destroyed.
+     *
+     * To reset $(D_PSYMBOL RefCounted) assign $(D_KEYWORD null).
+     *
+     * If the allocator wasn't set before, $(D_PSYMBOL defaultAllocator) will
+     * be used. If you need a different allocator, create a new
+     * $(D_PSYMBOL RefCounted) and assign it.
+     *
+     * Params:
+     *  rhs = New object.
+     *
+     * Returns: $(D_KEYWORD this).
+     */
+    ref typeof(this) opAssign(Payload!T rhs)
+    {
+        if (this.storage is null)
+        {
+            this.storage = allocator.make!Storage();
+            this.deleter = &separateDeleter!(Payload!T);
+        }
+        else if (this.storage > 1)
+        {
+            --this.storage;
+            this.storage = allocator.make!Storage();
+            this.deleter = &separateDeleter!(Payload!T);
+        }
+        else
+        {
+            finalize(this.storage.payload);
+            this.storage.payload = Payload!T.init;
+        }
+        this.storage.payload = rhs;
+        return this;
+    }
+
+    private @nogc unittest
+    {
+        auto rc = defaultAllocator.refCounted!int(5);
+        rc = defaultAllocator.make!int(7);
+        assert(*rc == 7);
+    }
+
+    /// Ditto.
+    ref typeof(this) opAssign(typeof(null))
+    {
+        if (this.storage is null)
+        {
+            return this;
+        }
+        else if (this.storage > 1)
+        {
+            --this.storage;
+        }
+        else
+        {
+            deleter(this.storage, allocator);
+        }
+        this.storage = null;
+
+        return this;
+    }
+
+    private @nogc unittest
+    {
+        RefCounted!int rc;
+        assert(!rc.isInitialized);
+        rc = null;
+        assert(!rc.isInitialized);
+    }
+
+    /// Ditto.
+    ref typeof(this) opAssign(typeof(this) rhs)
+    {
+        swap(this.allocator_, rhs.allocator_);
+        swap(this.storage, rhs.storage);
+        swap(this.deleter, rhs.deleter);
+        return this;
+    }
+
+    /**
+     * Returns: Reference to the owned object.
+     *
+     * Precondition: $(D_INLINECODE cound > 0).
+     */
+    inout(Payload!T) get() inout
+    in
+    {
+        assert(count > 0, "Attempted to access an uninitialized reference");
+    }
+    body
+    {
+        return this.storage.payload;
+    }
+
+    version (D_Ddoc)
+    {
+        /**
+         * Dereferences the pointer. It is defined only for pointers, not for
+         * reference types like classes, that can be accessed directly.
+         *
+         * Params:
+         *  op = Operation. 
+         *
+         * Returns: Reference to the pointed value.
+         */
+        ref inout(T) opUnary(string op)() inout
+        if (op == "*");
+    }
+    else static if (isPointer!(Payload!T))
+    {
+        ref inout(T) opUnary(string op)() inout
+        if (op == "*")
+        {
+            return *this.storage.payload;
+        }
+    }
+
+    /**
+     * Returns: Whether this $(D_PSYMBOL RefCounted) already has an internal 
+     *          storage.
+     */
+    @property bool isInitialized() const
+    {
+        return this.storage !is null;
+    }
+
+    /**
+     * Returns: The number of $(D_PSYMBOL RefCounted) instances that share
+     *          ownership over the same pointer (including $(D_KEYWORD this)).
+     *          If this $(D_PSYMBOL RefCounted) isn't initialized, returns `0`.
+     */
+    @property size_t count() const
+    {
+        return this.storage is null ? 0 : this.storage.counter;
+    }
+
+    mixin DefaultAllocator;
+    alias get this;
+}
+
+///
+unittest
+{
+    auto rc = RefCounted!int(defaultAllocator.make!int(5), defaultAllocator);
+    auto val = rc.get();
+
+    *val = 8;
+    assert(*rc.storage.payload == 8);
+
+    val = null;
+    assert(rc.storage.payload !is null);
+    assert(*rc.storage.payload == 8);
+
+    *rc = 9;
+    assert(*rc.storage.payload == 9);
+}
+
+private @nogc unittest
+{
+    auto rc = defaultAllocator.refCounted!int(5);
+
+    void func(RefCounted!int param) @nogc
+    {
+        assert(param.count == 2);
+        param = defaultAllocator.make!int(7);
+        assert(param.count == 1);
+        assert(*param == 7);
+    }
+    func(rc);
+    assert(rc.count == 1);
+    assert(*rc == 5);
+}
+
+private @nogc unittest
+{
+    RefCounted!int rc;
+
+    void func(RefCounted!int param) @nogc
+    {
+        assert(param.count == 0);
+        param = defaultAllocator.make!int(7);
+        assert(param.count == 1);
+        assert(*param == 7);
+    }
+    func(rc);
+    assert(rc.count == 0);
+}
+
+private unittest
+{
+    RefCounted!int rc1, rc2;
+    static assert(is(typeof(rc1 = rc2)));
+}
+
+version (unittest)
+{
+    private class A
+    {
+        uint *destroyed;
+
+        this(ref uint destroyed) @nogc
+        {
+            this.destroyed = &destroyed;
+        }
+
+        ~this() @nogc
+        {
+            ++(*destroyed);
+        }
+    }
+
+    private struct B
+    {
+        int prop;
+        @disable this();
+        this(int param1) @nogc
+        {
+            prop = param1;
+        }
+    }
+}
+
+private @nogc unittest
+{
+    uint destroyed;
+    auto a = defaultAllocator.make!A(destroyed);
+
+    assert(destroyed == 0);
+    {
+        auto rc = RefCounted!A(a, defaultAllocator);
+        assert(rc.count == 1);
+
+        void func(RefCounted!A rc) @nogc
+        {
+            assert(rc.count == 2);
+        }
+        func(rc);
+
+        assert(rc.count == 1);
+    }
+    assert(destroyed == 1);
+
+    RefCounted!int rc;
+    assert(rc.count == 0);
+    rc = defaultAllocator.make!int(8);
+    assert(rc.count == 1);
+}
+
+private @nogc unittest
+{
+    auto rc = RefCounted!int(defaultAllocator);
+    assert(!rc.isInitialized);
+    assert(rc.allocator is defaultAllocator);
+}
+
+private @nogc unittest
+{
+    auto rc = defaultAllocator.refCounted!int(5);
+    assert(rc.count == 1);
+
+    void func(RefCounted!int rc) @nogc
+    {
+        assert(rc.count == 2);
+        rc = null;
+        assert(!rc.isInitialized);
+        assert(rc.count == 0);
+    }
+
+    assert(rc.count == 1);
+    func(rc);
+    assert(rc.count == 1);
+
+    rc = null;
+    assert(!rc.isInitialized);
+    assert(rc.count == 0);
+}
+
+private unittest
+{
+    auto rc = defaultAllocator.refCounted!int(5);
+    assert(*rc == 5);
+
+    void func(RefCounted!int rc) @nogc
+    {
+        assert(rc.count == 2);
+        rc = defaultAllocator.refCounted!int(4);
+        assert(*rc == 4);
+        assert(rc.count == 1);
+    }
+    func(rc);
+    assert(*rc == 5);
+}
+
+private unittest
+{
+    static assert(is(typeof(RefCounted!int.storage.payload) == int*));
+    static assert(is(typeof(RefCounted!A.storage.payload) == A));
+
+    static assert(is(RefCounted!B));
+    static assert(is(RefCounted!A));
+}
+
+/**
+ * Constructs a new object of type $(D_PARAM T) and wraps it in a
+ * $(D_PSYMBOL RefCounted) using $(D_PARAM args) as the parameter list for
+ * the constructor of $(D_PARAM T).
+ *
+ * This function is more efficient than the using of $(D_PSYMBOL RefCounted)
+ * directly, since it allocates only ones (the internal storage and the
+ * object).
+ *
+ * Params:
+ *  T         = Type of the constructed object.
+ *  A         = Types of the arguments to the constructor of $(D_PARAM T).
+ *  allocator = Allocator.
+ *  args      = Constructor arguments of $(D_PARAM T).
+ * 
+ * Returns: Newly created $(D_PSYMBOL RefCounted!T).
+ *
+ * Precondition: $(D_INLINECODE allocator !is null)
+ */
+RefCounted!T refCounted(T, A...)(shared Allocator allocator, auto ref A args)
+if (!is(T == interface) && !isAbstractClass!T
+ && !isAssociativeArray!T && !isArray!T)
+in
+{
+    assert(allocator !is null);
+}
+body
+{
+    auto rc = typeof(return)(allocator);
+
+    const storageSize = alignedSize(stateSize!(RefCounted!T.Storage));
+    const size = alignedSize(stateSize!T + storageSize);
+
+    auto mem = (() @trusted => allocator.allocate(size))();
+    if (mem is null)
+    {
+        onOutOfMemoryError();
+    }
+    scope (failure)
+    {
+        () @trusted { allocator.deallocate(mem); }();
+    }
+    rc.storage = emplace!((RefCounted!T.Storage))(mem[0 .. storageSize]);
+
+    static if (is(T == class))
+    {
+        rc.storage.payload = emplace!T(mem[storageSize .. $], args);
+    }
+    else
+    {
+        auto ptr = (() @trusted => (cast(T*) mem[storageSize .. $].ptr))();
+        rc.storage.payload = emplace!T(ptr, args);
+    }
+    rc.deleter = &unifiedDeleter!(Payload!T);
+    return rc;
+}
+
+/**
+ * Constructs a new array with $(D_PARAM size) elements and wraps it in a
+ * $(D_PSYMBOL RefCounted).
+ *
+ * Params:
+ *  T         = Array type.
+ *  size      = Array size.
+ *  allocator = Allocator.
+ *
+ * Returns: Newly created $(D_PSYMBOL RefCounted!T).
+ *
+ * Precondition: $(D_INLINECODE allocator !is null
+ *                           && size <= size_t.max / ElementType!T.sizeof)
+ */
+RefCounted!T refCounted(T)(shared Allocator allocator, const size_t size)
+@trusted
+if (isArray!T)
+in
+{
+    assert(allocator !is null);
+    assert(size <= size_t.max / ElementType!T.sizeof);
+}
+body
+{
+    return RefCounted!T(allocator.make!T(size), allocator);
+}
+
+///
+unittest
+{
+    auto rc = defaultAllocator.refCounted!int(5);
+    assert(rc.count == 1);
+
+    void func(RefCounted!int param) @nogc
+    {
+        if (param.count == 2)
+        {
+            func(param);
+        }
+        else
+        {
+            assert(param.count == 3);
+        }
+    }
+    func(rc);
+
+    assert(rc.count == 1);
+}
+
+private @nogc unittest
+{
+    struct E
+    {
+    }
+    auto b = defaultAllocator.refCounted!B(15);
+    static assert(is(typeof(b.storage.payload) == B*));
+    static assert(is(typeof(b.prop) == int));
+    static assert(!is(typeof(defaultAllocator.refCounted!B())));
+
+    static assert(is(typeof(defaultAllocator.refCounted!E())));
+    static assert(!is(typeof(defaultAllocator.refCounted!E(5))));
+    {
+        auto rc = defaultAllocator.refCounted!B(3);
+        assert(rc.get().prop == 3);
+    }
+    {
+        auto rc = defaultAllocator.refCounted!E();
+        assert(rc.count);
+    }
+}
+
+private @nogc unittest
+{
+    auto rc = defaultAllocator.refCounted!(int[])(5);
+    assert(rc.length == 5);
+}
+
+private @nogc unittest
+{
+    auto p1 = defaultAllocator.make!int(5);
+    auto p2 = p1;
+    auto rc = RefCounted!int(p1, defaultAllocator);
+    assert(rc.get() is p2);
+}
+
+private @nogc unittest
+{
+    static bool destroyed = false;
+
+    struct F
+    {
+        ~this() @nogc
+        {
+            destroyed = true;
+        }
+    }
+    {
+        auto rc = defaultAllocator.refCounted!F();
+    }
+    assert(destroyed);
+}
+
+/**
+ * $(D_PSYMBOL Unique) stores an object that gets destroyed at the end of its scope.
+ *
+ * Params:
+ *  T = Value type.
+ */
+struct Unique(T)
+{
+    private Payload!T payload;
+
+    invariant
+    {
+        assert(payload is null || allocator_ !is null);
+    }
+
+    /**
+     * Takes ownership over $(D_PARAM value), setting the counter to 1.
+     * $(D_PARAM value) may be a pointer, an object or a dynamic array.
+     *
+     * Params:
+     *  value     = Value whose ownership is taken over.
+     *  allocator = Allocator used to destroy the $(D_PARAM value) and to
+     *              allocate/deallocate internal storage.
+     *
+     * Precondition: $(D_INLINECODE allocator !is null)
+     */
+    this(Payload!T value, shared Allocator allocator = defaultAllocator)
+    {
+        this(allocator);
+        this.payload = value;
+    }
+
+    /// Ditto.
+    this(shared Allocator allocator)
+    in
+    {
+        assert(allocator !is null);
+    }
+    body
+    {
+        this.allocator_ = allocator;
+    }
+
+    /**
+     * $(D_PSYMBOL Unique) is noncopyable.
+     */
+    @disable this(this);
+
+    /**
+     * Destroys the owned object.
+     */
+    ~this()
+    {
+        allocator.dispose(this.payload);
+    }
+
+    /**
+     * Initialized this $(D_PARAM Unique) and takes ownership over
+     * $(D_PARAM rhs).
+     *
+     * To reset $(D_PSYMBOL Unique) assign $(D_KEYWORD null).
+     *
+     * If the allocator wasn't set before, $(D_PSYMBOL defaultAllocator) will
+     * be used. If you need a different allocator, create a new
+     * $(D_PSYMBOL Unique) and assign it.
+     *
+     * Params:
+     *  rhs = New object.
+     *
+     * Returns: $(D_KEYWORD this).
+     */
+    ref typeof(this) opAssign(Payload!T rhs)
+    {
+        allocator.dispose(this.payload);
+        this.payload = rhs;
+        return this;
+    }
+
+    /// Ditto.
+    ref typeof(this) opAssign(typeof(null))
+    {
+        allocator.dispose(this.payload);
+        return this;
+    }
+
+    /// Ditto.
+    ref typeof(this) opAssign(typeof(this) rhs)
+    {
+        swap(this.allocator_, rhs.allocator_);
+        swap(this.payload, rhs.payload);
+
+        return this;
+    }
+
+    ///
+    @nogc unittest
+    {
+        auto rc = defaultAllocator.unique!int(5);
+        rc = defaultAllocator.make!int(7);
+        assert(*rc == 7);
+    }
+
+    /**
+     * Returns: Reference to the owned object.
+     */
+    inout(Payload!T) get() inout
+    {
+        return this.payload;
+    }
+
+    version (D_Ddoc)
+    {
+        /**
+         * Dereferences the pointer. It is defined only for pointers, not for
+         * reference types like classes, that can be accessed directly.
+         *
+         * Params:
+         *  op = Operation. 
+         *
+         * Returns: Reference to the pointed value.
+         */
+        ref inout(T) opUnary(string op)() inout
+        if (op == "*");
+    }
+    else static if (isPointer!(Payload!T))
+    {
+        ref inout(T) opUnary(string op)() inout
+        if (op == "*")
+        {
+            return *this.payload;
+        }
+    }
+
+    /**
+     * Returns: Whether this $(D_PSYMBOL Unique) holds some value.
+     */
+    @property bool isInitialized() const
+    {
+        return this.payload !is null;
+    }
+
+    ///
+    @nogc unittest
+    {
+        Unique!int u;
+        assert(!u.isInitialized);
+    }
+
+    /**
+     * Sets the internal pointer to $(D_KEYWORD). The allocator isn't changed.
+     *
+     * Returns: Reference to the owned object.
+     */
+    Payload!T release()
+    {
+        auto payload = this.payload;
+        this.payload = null;
+        return payload;
+    }
+
+    ///
+    @nogc unittest
+    {
+        auto u = defaultAllocator.unique!int(5);
+        assert(u.isInitialized);
+
+        auto i = u.release();
+        assert(*i == 5);
+        assert(!u.isInitialized);
+    }
+
+    mixin DefaultAllocator;
+    alias get this;
+}
+
+///
+@nogc unittest
+{
+    auto p = defaultAllocator.make!int(5);
+    auto s = Unique!int(p, defaultAllocator);
+    assert(*s == 5);
+}
+
+///
+@nogc unittest
+{
+    static bool destroyed = false;
+
+    struct F
+    {
+        ~this() @nogc
+        {
+            destroyed = true;
+        }
+    }
+    {
+        auto s = Unique!F(defaultAllocator.make!F(), defaultAllocator);
+    }
+    assert(destroyed);
+}
+
+/**
+ * Constructs a new object of type $(D_PARAM T) and wraps it in a
+ * $(D_PSYMBOL Unique) using $(D_PARAM args) as the parameter list for
+ * the constructor of $(D_PARAM T).
+ *
+ * Params:
+ *  T         = Type of the constructed object.
+ *  A         = Types of the arguments to the constructor of $(D_PARAM T).
+ *  allocator = Allocator.
+ *  args      = Constructor arguments of $(D_PARAM T).
+ * 
+ * Returns: Newly created $(D_PSYMBOL Unique!T).
+ *
+ * Precondition: $(D_INLINECODE allocator !is null)
+ */
+Unique!T unique(T, A...)(shared Allocator allocator, auto ref A args)
+if (!is(T == interface) && !isAbstractClass!T
+ && !isAssociativeArray!T && !isArray!T)
+in
+{
+    assert(allocator !is null);
+}
+body
+{
+    auto payload = allocator.make!(T, A)(args);
+    return Unique!T(payload, allocator);
+}
+
+/**
+ * Constructs a new array with $(D_PARAM size) elements and wraps it in a
+ * $(D_PSYMBOL Unique).
+ *
+ * Params:
+ *  T         = Array type.
+ *  size      = Array size.
+ *  allocator = Allocator.
+ *
+ * Returns: Newly created $(D_PSYMBOL Unique!T).
+ *
+ * Precondition: $(D_INLINECODE allocator !is null
+ *                           && size <= size_t.max / ElementType!T.sizeof)
+ */
+Unique!T unique(T)(shared Allocator allocator, const size_t size)
+@trusted
+if (isArray!T)
+in
+{
+    assert(allocator !is null);
+    assert(size <= size_t.max / ElementType!T.sizeof);
+}
+body
+{
+    auto payload = allocator.resize!(ElementType!T)(null, size);
+    return Unique!T(payload, allocator);
+}
+
+private unittest
+{
+    static assert(is(typeof(defaultAllocator.unique!B(5))));
+    static assert(is(typeof(defaultAllocator.unique!(int[])(5))));
+}
+
+private unittest
+{
+    auto s = defaultAllocator.unique!int(5);
+    assert(*s == 5);
+
+    s = null;
+    assert(s is null);
+}
+
+private unittest
+{
+    auto s = defaultAllocator.unique!int(5);
+    assert(*s == 5);
+
+    s = defaultAllocator.unique!int(4);
+    assert(*s == 4);
+}
+
+private @nogc unittest
+{
+    auto p1 = defaultAllocator.make!int(5);
+    auto p2 = p1;
+
+    auto rc = Unique!int(p1, defaultAllocator);
+    assert(rc.get() is p2);
+}
+
+private @nogc unittest
+{
+    auto rc = Unique!int(defaultAllocator);
+    assert(rc.allocator is defaultAllocator);
+}

source/tanya/memory/types.d

@@ -1,458 +0,0 @@
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-/**
- * Copyright: Eugene Wissner 2016-2017.
- * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
- *                  Mozilla Public License, v. 2.0).
- * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
- */
-module tanya.memory.types;
-
-import core.exception;
-import std.algorithm.comparison;
-import std.algorithm.mutation;
-import std.conv;
-import std.traits;
-import tanya.memory;
-
-/**
- * Reference-counted object containing a $(D_PARAM T) value as payload.
- * $(D_PSYMBOL RefCounted) keeps track of all references of an object, and
- * when the reference count goes down to zero, frees the underlying store.
- *
- * Params:
- *  T = Type of the reference-counted value.
- */
-struct RefCounted(T)
-{
-    static if (is(T == class) || is(T == interface))
-    {
-        private alias Payload = T;
-    }
-    else
-    {
-        private alias Payload = T*;
-    }
-
-    private class Storage
-    {
-        private Payload payload;
-        private size_t counter = 1;
-
-        private final size_t opUnary(string op)() pure nothrow @safe @nogc
-            if (op == "--" || op == "++")
-        in
-        {
-            assert(counter > 0);
-        }
-        body
-        {
-            mixin("return " ~ op ~ "counter;");
-        }
-
-        private final int opCmp(size_t counter) const pure nothrow @safe @nogc
-        {
-            if (this.counter > counter)
-            {
-                return 1;
-            }
-            else if (this.counter < counter)
-            {
-                return -1;
-            }
-            else
-            {
-                return 0;
-            }
-        }
-
-        private final int opEquals(size_t counter) const pure nothrow @safe @nogc
-        {
-            return this.counter == counter;
-        }
-    }
-
-    private final class RefCountedStorage : Storage
-    {
-        private shared Allocator allocator;
-
-        this(shared Allocator allocator) pure nothrow @safe @nogc
-        in
-        {
-            assert(allocator !is null);
-        }
-        body
-        {
-            this.allocator = allocator;
-        }
-
-        ~this() nothrow @nogc
-        {
-            allocator.dispose(payload);
-        }
-    }
-
-    private Storage storage;
-
-    invariant
-    {
-        assert(storage is null || allocator_ !is null);
-    }
-
-    /**
-     * Takes ownership over $(D_PARAM value), setting the counter to 1.
-     * $(D_PARAM value) may be a pointer, an object or a dynamic array.
-     *
-     * Params:
-     *  value     = Value whose ownership is taken over.
-     *  allocator = Allocator used to destroy the $(D_PARAM value) and to
-     *              allocate/deallocate internal storage.
-     *
-     * Precondition: $(D_INLINECODE allocator !is null)
-     */
-    this(Payload value, shared Allocator allocator = defaultAllocator)
-    {
-        this(allocator);
-        storage = allocator.make!RefCountedStorage(allocator);
-        move(value, storage.payload);
-    }
-
-    /// Ditto.
-    this(shared Allocator allocator)
-    in
-    {
-        assert(allocator !is null);
-    }
-    body
-    {
-        this.allocator_ = allocator;
-    }
-
-    /**
-     * Increases the reference counter by one.
-     */
-    this(this)
-    {
-        if (count != 0)
-        {
-            ++storage;
-        }
-    }
-
-    /**
-     * Decreases the reference counter by one.
-     *
-     * If the counter reaches 0, destroys the owned object.
-     */
-    ~this()
-    {
-        if (storage !is null && !(storage.counter && --storage))
-        {
-            allocator_.dispose(storage);
-        }
-    }
-
-    /**
-     * Takes ownership over $(D_PARAM rhs). Initializes this
-     * $(D_PSYMBOL RefCounted) if needed.
-     *
-     * If it is the last reference of the previously owned object,
-     * it will be destroyed.
-     *
-     * To reset the $(D_PSYMBOL RefCounted) assign $(D_KEYWORD null).
-     *
-     * If the allocator wasn't set before, $(D_PSYMBOL defaultAllocator) will
-     * be used. If you need a different allocator, create a new
-     * $(D_PSYMBOL RefCounted) and assign it.
-     *
-     * Params:
-     *  rhs = $(D_KEYWORD this).
-     */
-    ref typeof(this) opAssign(Payload rhs)
-    {
-        if (storage is null)
-        {
-            storage = allocator.make!RefCountedStorage(allocator);
-        }
-        else if (storage > 1)
-        {
-            --storage;
-            storage = allocator.make!RefCountedStorage(allocator);
-        }
-        else if (cast(RefCountedStorage) storage is null)
-        {
-            // Created with refCounted. Always destroyed togethter with the pointer.
-            assert(storage.counter != 0);
-            allocator.dispose(storage);
-            storage = allocator.make!RefCountedStorage(allocator);
-        }
-        else
-        {
-            allocator.dispose(storage.payload);
-        }
-        move(rhs, storage.payload);
-        return this;
-    }
-
-    /// Ditto.
-    ref typeof(this) opAssign(typeof(null))
-    {
-        if (storage is null)
-        {
-            return this;
-        }
-        else if (storage > 1)
-        {
-            --storage;
-            storage = null;
-        }
-        else if (cast(RefCountedStorage) storage is null)
-        {
-            // Created with refCounted. Always destroyed togethter with the pointer.
-            assert(storage.counter != 0);
-            allocator.dispose(storage);
-            return this;
-        }
-        else
-        {
-            allocator.dispose(storage.payload);
-        }
-        return this;
-    }
-
-    /// Ditto.
-    ref typeof(this) opAssign(typeof(this) rhs)
-    {
-        swap(allocator_, rhs.allocator_);
-        swap(storage, rhs.storage);
-        return this;
-    }
-
-    /**
-     * Returns: Reference to the owned object.
-     */
-    inout(Payload) get() inout pure nothrow @safe @nogc
-    in
-    {
-        assert(count > 0, "Attempted to access an uninitialized reference.");
-    }
-    body
-    {
-        return storage.payload;
-    }
-
-    static if (isPointer!Payload)
-    {
-        /**
-         * Params:
-         *  op = Operation. 
-         *
-         * Dereferences the pointer. It is defined only for pointers, not for
-         * reference types like classes, that can be accessed directly.
-         *
-         * Returns: Reference to the pointed value.
-         */
-        ref T opUnary(string op)()
-            if (op == "*")
-        {
-            return *storage.payload;
-        }
-    }
-
-    /**
-     * Returns: Whether this $(D_PSYMBOL RefCounted) already has an internal 
-     *          storage.
-     */
-    @property bool isInitialized() const
-    {
-        return storage !is null;
-    }
-
-    /**
-     * Returns: The number of $(D_PSYMBOL RefCounted) instances that share
-     *          ownership over the same pointer (including $(D_KEYWORD this)).
-     *          If this $(D_PSYMBOL RefCounted) isn't initialized, returns `0`.
-     */
-    @property size_t count() const
-    {
-        return storage is null ? 0 : storage.counter;
-    }
-
-    mixin DefaultAllocator;
-    alias get this;
-}
-
-///
-unittest
-{
-    auto rc = RefCounted!int(defaultAllocator.make!int(5), defaultAllocator);
-    auto val = rc.get;
-
-    *val = 8;
-    assert(*rc.storage.payload == 8);
-
-    val = null;
-    assert(rc.storage.payload !is null);
-    assert(*rc.storage.payload == 8);
-
-    *rc = 9;
-    assert(*rc.storage.payload == 9);
-}
-
-version (unittest)
-{
-    private class A
-    {
-        uint *destroyed;
-
-        this(ref uint destroyed) @nogc
-        {
-            this.destroyed = &destroyed;
-        }
-
-        ~this() @nogc
-        {
-            ++(*destroyed);
-        }
-    }
-
-    private struct B
-    {
-        int prop;
-        @disable this();
-        this(int param1) @nogc
-        {
-            prop = param1;
-        }
-    }
-}
-
-private unittest
-{
-    uint destroyed;
-    auto a = defaultAllocator.make!A(destroyed);
-
-    assert(destroyed == 0);
-    {
-        auto rc = RefCounted!A(a, defaultAllocator);
-        assert(rc.count == 1);
-
-        void func(RefCounted!A rc)
-        {
-            assert(rc.count == 2);
-        }
-        func(rc);
-
-        assert(rc.count == 1);
-    }
-    assert(destroyed == 1);
-
-    RefCounted!int rc;
-    assert(rc.count == 0);
-    rc = defaultAllocator.make!int(8);
-    assert(rc.count == 1);
-}
-
-private unittest
-{
-    static assert(is(typeof(RefCounted!int.storage.payload) == int*));
-    static assert(is(typeof(RefCounted!A.storage.payload) == A));
-
-    static assert(is(RefCounted!B));
-    static assert(is(RefCounted!A));
-}
-
-/**
- * Constructs a new object of type $(D_PARAM T) and wraps it in a
- * $(D_PSYMBOL RefCounted) using $(D_PARAM args) as the parameter list for
- * the constructor of $(D_PARAM T).
- *
- * This function is more efficient than the using of $(D_PSYMBOL RefCounted)
- * directly, since it allocates only ones (the internal storage and the
- * object).
- *
- * Params:
- *  T         = Type of the constructed object.
- *  A         = Types of the arguments to the constructor of $(D_PARAM T).
- *  allocator = Allocator.
- *  args      = Constructor arguments of $(D_PARAM T).
- * 
- * Returns: Newly created $(D_PSYMBOL RefCounted!T).
- */
-RefCounted!T refCounted(T, A...)(shared Allocator allocator, auto ref A args)
-    if (!is(T == interface) && !isAbstractClass!T
-         && !isArray!T && !isAssociativeArray!T)
-{
-    auto rc = typeof(return)(allocator);
-
-    immutable storageSize = alignedSize(stateSize!(RefCounted!T.Storage));
-    immutable size = alignedSize(stateSize!T + storageSize);
-
-    auto mem = (() @trusted => allocator.allocate(size))();
-    if (mem is null)
-    {
-        onOutOfMemoryError();
-    }
-    scope (failure)
-    {
-        () @trusted { allocator.deallocate(mem); }();
-    }
-    rc.storage = emplace!(RefCounted!T.Storage)(mem[0 .. storageSize]);
-
-    static if (is(T == class))
-    {
-        rc.storage.payload = emplace!T(mem[storageSize .. $], args);
-    }
-    else
-    {
-        auto ptr = (() @trusted => (cast(T*) mem[storageSize .. $].ptr))();
-        rc.storage.payload = emplace!T(ptr, args);
-    }
-    return rc;
-}
-
-///
-unittest
-{
-    auto rc = defaultAllocator.refCounted!int(5);
-    assert(rc.count == 1);
-
-    void func(RefCounted!int param)
-    {
-        if (param.count == 2)
-        {
-            func(param);
-        }
-        else
-        {
-            assert(param.count == 3);
-        }
-    }
-    func(rc);
-
-    assert(rc.count == 1);
-}
-
-private @nogc unittest
-{
-    struct E
-    {
-    }
-    auto b = defaultAllocator.refCounted!B(15);
-    static assert(is(typeof(b.storage.payload) == B*));
-    static assert(is(typeof(b.prop) == int));
-    static assert(!is(typeof(defaultAllocator.refCounted!B())));
-
-    static assert(is(typeof(defaultAllocator.refCounted!E())));
-    static assert(!is(typeof(defaultAllocator.refCounted!E(5))));
-    {
-        auto rc = defaultAllocator.refCounted!B(3);
-        assert(rc.get.prop == 3);
-    }
-    {
-        auto rc = defaultAllocator.refCounted!E();
-        assert(rc.count);
-    }
-}

source/tanya/net/inet.d

@@ -0,0 +1,356 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Internet utilities.
+ *
+ * Copyright: Eugene Wissner 2016-2017.
+ * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
+ *                  Mozilla Public License, v. 2.0).
+ * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
+ */
+module tanya.net.inet;
+
+import std.math;
+import std.range.primitives;
+import std.traits;
+
+version (unittest)
+{
+    version (Windows)
+    {
+        import core.sys.windows.winsock2;
+        version = PlattformUnittest;
+    }
+    else version (Posix)
+    {
+        import core.sys.posix.arpa.inet;
+        version = PlattformUnittest;
+    }
+}
+
+/**
+ * Represents an unsigned integer as an $(D_KEYWORD ubyte) range.
+ *
+ * The range is bidirectional. The byte order is always big-endian.
+ *
+ * It can accept any unsigned integral type but the value should fit
+ * in $(D_PARAM L) bytes.
+ *
+ * Params:
+ *  L = Desired range length.
+ */
+struct NetworkOrder(uint L)
+    if (L > ubyte.sizeof && L <= ulong.sizeof)
+{
+    static if (L > uint.sizeof)
+    {
+        private alias StorageType = ulong;
+    }
+    else static if (L > ushort.sizeof)
+    {
+        private alias StorageType = uint;
+    }
+    else static if (L > ubyte.sizeof)
+    {
+        private alias StorageType = ushort;
+    }
+    else
+    {
+        private alias StorageType = ubyte;
+    }
+
+    private StorageType value;
+    private size_t size = L;
+
+    const pure nothrow @safe @nogc invariant
+    {
+        assert(this.size <= L);
+    }
+
+    /**
+     * Constructs a new range.
+     *
+     * $(D_PARAM T) can be any unsigned type but $(D_PARAM value) cannot be
+     * larger than the maximum can be stored in $(D_PARAM L) bytes. Otherwise
+     * an assertion failure will be caused.
+     *
+     * Params:
+     *  T      = Value type.
+     *  value  = The value should be represented by this range.
+     *
+     * Precondition: $(D_INLINECODE value <= 2 ^^ (length * 8) - 1).
+     */
+    this(T)(const T value)
+        if (isUnsigned!T)
+    in
+    {
+        assert(value <= pow(2, L * 8) - 1);
+    }
+    body
+    {
+        this.value = value & StorageType.max;
+    }
+
+    /**
+     * Returns: LSB.
+     *
+     * Precondition: $(D_INLINECODE length > 0).
+     */
+    @property ubyte back() const
+    in
+    {
+        assert(this.length > 0);
+    }
+    body
+    {
+        return this.value & 0xff;
+    }
+
+    /**
+     * Returns: MSB.
+     *
+     * Precondition: $(D_INLINECODE length > 0).
+     */
+    @property ubyte front() const
+    in
+    {
+        assert(this.length > 0);
+    }
+    body
+    {
+        return (this.value >> ((this.length - 1) * 8)) & 0xff;
+    }
+
+    /**
+     * Eliminates the LSB.
+     *
+     * Precondition: $(D_INLINECODE length > 0).
+     */
+    void popBack()
+    in
+    {
+        assert(this.length > 0);
+    }
+    body
+    {
+        this.value >>= 8;
+        --this.size;
+    }
+
+    /**
+     * Eliminates the MSB.
+     *
+     * Precondition: $(D_INLINECODE length > 0).
+     */
+    void popFront()
+    in
+    {
+        assert(this.length > 0);
+    }
+    body
+    {
+        this.value &= StorageType.max >> ((StorageType.sizeof - this.length) * 8);
+        --this.size;
+    }
+
+    /**
+     * Returns: Copy of this range.
+     */
+    typeof(this) save() const
+    {
+        return this;
+    }
+
+    /**
+     * Returns: Whether the range is empty.
+     */
+    @property bool empty() const
+    {
+        return this.length == 0;
+    }
+
+    /**
+     * Returns: Byte length.
+     */
+    @property size_t length() const
+    {
+        return this.size;
+    }
+}
+
+///
+pure nothrow @safe @nogc unittest
+{
+    auto networkOrder = NetworkOrder!3(0xae34e2u);
+    assert(!networkOrder.empty);
+    assert(networkOrder.front == 0xae);
+
+    networkOrder.popFront();
+    assert(networkOrder.length == 2);
+    assert(networkOrder.front == 0x34);
+    assert(networkOrder.back == 0xe2);
+
+    networkOrder.popBack();
+    assert(networkOrder.length == 1);
+    assert(networkOrder.front == 0x34);
+    assert(networkOrder.front == 0x34);
+
+    networkOrder.popFront();
+    assert(networkOrder.empty);
+}
+
+// Static.
+private unittest
+{
+    static assert(isBidirectionalRange!(NetworkOrder!4));
+    static assert(isBidirectionalRange!(NetworkOrder!8));
+    static assert(!is(NetworkOrder!9));
+    static assert(!is(NetworkOrder!1));
+}
+
+// Tests against the system's htonl, htons.
+version (PlattformUnittest)
+{
+    private unittest
+    {
+        for (uint counter; counter <= 8 * uint.sizeof; ++counter)
+        {
+            const value = pow(2, counter) - 1;
+            const inNetworkOrder = htonl(value);
+            const p = cast(ubyte*) &inNetworkOrder;
+            auto networkOrder = NetworkOrder!4(value);
+
+            assert(networkOrder.length == 4);
+            assert(!networkOrder.empty);
+            assert(networkOrder.front == *p);
+            assert(networkOrder.back == *(p + 3));
+
+            networkOrder.popBack();
+            assert(networkOrder.length == 3);
+            assert(networkOrder.front == *p);
+            assert(networkOrder.back == *(p + 2));
+
+            networkOrder.popFront();
+            assert(networkOrder.length == 2);
+            assert(networkOrder.front == *(p + 1));
+            assert(networkOrder.back == *(p + 2));
+
+            networkOrder.popFront();
+            assert(networkOrder.length == 1);
+            assert(networkOrder.front == *(p + 2));
+            assert(networkOrder.back == *(p + 2));
+
+            networkOrder.popBack();
+            assert(networkOrder.length == 0);
+            assert(networkOrder.empty);
+        }
+
+        for (ushort counter; counter <= 8 * ushort.sizeof; ++counter)
+        {
+            const value = cast(ushort) (pow(2, counter) - 1);
+            const inNetworkOrder = htons(value);
+            const p = cast(ubyte*) &inNetworkOrder;
+
+            auto networkOrder = NetworkOrder!2(value);
+
+            assert(networkOrder.length == 2);
+            assert(!networkOrder.empty);
+            assert(networkOrder.front == *p);
+            assert(networkOrder.back == *(p + 1));
+
+            networkOrder.popBack();
+            assert(networkOrder.length == 1);
+            assert(networkOrder.front == *p);
+            assert(networkOrder.back == *p);
+
+            networkOrder.popBack();
+            assert(networkOrder.length == 0);
+            assert(networkOrder.empty);
+
+            networkOrder = NetworkOrder!2(value);
+
+            networkOrder.popFront();
+            assert(networkOrder.length == 1);
+            assert(networkOrder.front == *(p + 1));
+            assert(networkOrder.back == *(p + 1));
+
+            networkOrder.popFront();
+            assert(networkOrder.length == 0);
+            assert(networkOrder.empty);
+        }
+    }
+}
+
+/**
+ * Converts the $(D_KEYWORD ubyte) input range $(D_PARAM range) to
+ * $(D_PARAM T).
+ *
+ * The byte order of $(D_PARAM r) is assumed to be big-endian. The length
+ * cannot be larger than $(D_INLINECODE T.sizeof). Otherwise an assertion
+ * failure will be caused.
+ *
+ * Params:
+ *  T     = Desired return type.
+ *  R     = Range type.
+ *  range = Input range.
+ *
+ * Returns: Integral representation of $(D_PARAM range) with the host byte
+ *          order.
+ */
+T toHostOrder(T = size_t, R)(R range)
+    if (isInputRange!R
+     && !isInfinite!R
+     && is(Unqual!(ElementType!R) == ubyte)
+     && isUnsigned!T)
+{
+    T ret;
+    ushort pos = T.sizeof * 8;
+
+    for (; !range.empty && range.front == 0; pos -= 8, range.popFront())
+    {
+    }
+    for (; !range.empty; range.popFront())
+    {
+        assert(pos != 0);
+        pos -= 8;
+        ret |= (cast(T) range.front) << pos;
+    }
+
+    return ret >> pos;
+}
+
+///
+pure nothrow @safe @nogc unittest
+{
+    const value = 0xae34e2u;
+    auto networkOrder = NetworkOrder!4(value);
+    assert(networkOrder.toHostOrder() == value);
+}
+
+// Tests against the system's htonl, htons.
+version (PlattformUnittest)
+{
+    private unittest
+    {
+        for (uint counter; counter <= 8 * uint.sizeof; ++counter)
+        {
+            const value = pow(2, counter) - 1;
+            const inNetworkOrder = htonl(value);
+            const p = cast(ubyte*) &inNetworkOrder;
+            auto networkOrder = NetworkOrder!4(value);
+
+            assert(p[0 .. uint.sizeof].toHostOrder() == value);
+        }
+        for (ushort counter; counter <= 8 * ushort.sizeof; ++counter)
+        {
+            const value = cast(ushort) (pow(2, counter) - 1);
+            const inNetworkOrder = htons(value);
+            const p = cast(ubyte*) &inNetworkOrder;
+            auto networkOrder = NetworkOrder!2(value);
+
+            assert(p[0 .. ushort.sizeof].toHostOrder() == value);
+        }
+    }
+}

source/tanya/net/package.d

@@ -0,0 +1,16 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Network programming.
+ *
+ * Copyright: Eugene Wissner 2017.
+ * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
+ *                  Mozilla Public License, v. 2.0).
+ * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
+ */
+module tanya.net;
+
+public import tanya.net.inet;
+public import tanya.net.uri;

source/tanya/net/uri.d

@@ -0,0 +1,573 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * URL parser.
+ *
+ * Copyright: Eugene Wissner 2017.
+ * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
+ *                  Mozilla Public License, v. 2.0).
+ * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
+ */
+module tanya.net.uri;
+
+import std.ascii : isAlphaNum, isDigit;
+import std.uni : isAlpha, isNumber;
+import tanya.memory;
+
+/**
+ * Thrown if an invalid URI was specified.
+ */
+final class URIException : Exception
+{
+    /**
+     * Params:
+     *  msg  = The message for the exception.
+     *  file = The file where the exception occurred.
+     *  line = The line number where the exception occurred.
+     *  next = The previous exception in the chain of exceptions, if any.
+     */
+    this(string msg,
+         string file = __FILE__,
+         size_t line = __LINE__,
+         Throwable next = null) @nogc @safe pure nothrow
+    {
+        super(msg, file, line, next);
+    }
+}
+
+/**
+ * A Unique Resource Locator.
+ */
+struct URL
+{
+    /// The URL scheme.
+    const(char)[] scheme;
+
+    /// The username.
+    const(char)[] user;
+
+    /// The password.
+    const(char)[] pass;
+
+    /// The hostname.
+    const(char)[] host;
+
+    /// The port number.
+    ushort port;
+
+    /// The path.
+    const(char)[] path;
+
+    /// The query string.
+    const(char)[] query;
+
+    /// The anchor.
+    const(char)[] fragment;
+
+    /**
+     * Attempts to parse an URL from a string.
+     * Output string data (scheme, user, etc.) are just slices of input string
+     * (i.e., no memory allocation and copying).
+     *
+     * Params:
+     *  source = The string containing the URL.
+     *
+     * Throws: $(D_PSYMBOL URIException) if the URL is malformed.
+     */
+    this(const char[] source) pure @nogc
+    {
+        ptrdiff_t pos = -1, endPos = source.length, start;
+
+        foreach (i, ref c; source)
+        {
+            if (pos == -1 && c == ':')
+            {
+                pos = i;
+            }
+            if (endPos == source.length && (c == '?' || c == '#'))
+            {
+                endPos = i;
+            }
+        }
+
+        // Check if the colon is a part of the scheme or the port and parse
+        // the appropriate part.
+        if (source.length > 1 && source[0] == '/' && source[1] == '/')
+        {
+            // Relative scheme.
+            start = 2;
+        }
+        else if (pos > 0)
+        {
+            // Validate scheme:
+            // [ toLower(alpha) | digit | "+" | "-" | "." ]
+            foreach (ref c; source[0 .. pos])
+            {
+                if (!c.isAlphaNum && c != '+' && c != '-' && c != '.')
+                {
+                    goto ParsePath;
+                }
+            }
+
+            if (source.length == pos + 1) // only "scheme:" is available.
+            {
+                this.scheme = source[0 .. $ - 1];
+                return;
+            }
+            else if (source.length > pos + 1 && source[pos + 1] == '/')
+            {
+                this.scheme = source[0 .. pos];
+
+                if (source.length > pos + 2 && source[pos + 2] == '/')
+                {
+                    start = pos + 3;
+
+                    if (source.length <= start)
+                    {
+                        // Only "scheme://" is available.
+                        return;
+                    }
+                    if (this.scheme == "file" && source[start] == '/')
+                    {
+                        // Windows drive letters.
+                        if (source.length - start > 2
+                         && source[start + 2] == ':')
+                        {
+                            ++start;
+                        }
+                        goto ParsePath;
+                    }
+                }
+                else
+                {
+                    start = pos + 1;
+                    goto ParsePath;
+                }
+            }
+            else
+            {
+                // Schemas like mailto: and zlib: may not have any slash after
+                // them.
+                if (!parsePort(source[pos .. $]))
+                {
+                    this.scheme = source[0 .. pos];
+                    start = pos + 1;
+                    goto ParsePath;
+                }
+            }
+        }
+        else if (pos == 0 && parsePort(source[pos .. $]))
+        {
+            // An URL shouldn't begin with a port number.
+            throw defaultAllocator.make!URIException("URL begins with port");
+        }
+        else
+        {
+            goto ParsePath;
+        }
+
+        // Parse host.
+        pos = -1;
+        for (ptrdiff_t i = start; i < source.length; ++i)
+        {
+            if (source[i] == '@')
+            {
+                pos = i;
+            }
+            else if (source[i] == '/')
+            {
+                endPos = i;
+                break;
+            }
+        }
+
+        // Check for login and password.
+        if (pos != -1)
+        {
+            // *( unreserved / pct-encoded / sub-delims / ":" )
+            foreach (i, c; source[start .. pos])
+            {
+                if (c == ':')
+                {
+                    if (this.user is null)
+                    {
+                        this.user = source[start .. start + i];
+                        this.pass = source[start + i + 1 .. pos]; 
+                    }
+                }
+                else if (!c.isAlpha &&
+                         !c.isNumber &&
+                         c != '!' &&
+                         c != ';' &&
+                         c != '=' &&
+                         c != '_' &&
+                         c != '~' &&
+                         !(c >= '$' && c <= '.'))
+                {
+                    this.scheme = this.user = this.pass = null;
+                    throw make!URIException(defaultAllocator,
+                                            "Restricted characters in user information");
+                }
+            }
+            if (this.user is null)
+            {
+                this.user = source[start .. pos];
+            }
+
+            start = ++pos;
+        }
+
+        pos = endPos;
+        if (endPos <= 1 || source[start] != '[' || source[endPos - 1] != ']')
+        {
+            // Short circuit portscan.
+            // IPv6 embedded address.
+            for (ptrdiff_t i = endPos - 1; i >= start; --i)
+            {
+                if (source[i] == ':')
+                {
+                    pos = i;
+                    if  (this.port == 0 && !parsePort(source[i .. endPos]))
+                    {
+                        this.scheme = this.user = this.pass = null;
+                        throw defaultAllocator.make!URIException("Invalid port");
+                    }
+                    break;
+                }
+            }
+        }
+
+        // Check if we have a valid host, if we don't reject the string as URL.
+        if (pos <= start)
+        {
+            this.scheme = this.user = this.pass = null;
+            throw defaultAllocator.make!URIException("Invalid host");
+        }
+
+        this.host = source[start .. pos];
+
+        if (endPos == source.length)
+        {
+            return;
+        }
+
+        start = endPos;
+
+    ParsePath:
+        endPos = source.length;
+        pos = -1;
+        foreach (i, ref c; source[start .. $])
+        {
+            if (c == '?' && pos == -1)
+            {
+                pos = start + i;
+            }
+            else if (c == '#')
+            {
+                endPos = start + i;
+                break;
+            }
+        }
+        if (pos == -1)
+        {
+            pos = endPos;
+        }
+
+        if (pos > start)
+        {
+            this.path = source[start .. pos];
+        }
+        if (endPos >= ++pos)
+        {
+            this.query = source[pos .. endPos];
+        }
+        if (++endPos <= source.length)
+        {
+            this.fragment = source[endPos .. $];
+        }
+    }
+
+    /*
+     * Attempts to parse and set the port.
+     *
+     * Params:
+     *  port = String beginning with a colon followed by the port number and
+     *         an optional path (query string and/or fragment), like:
+     *         `:12345/some_path` or `:12345`.
+     *
+     * Returns: Whether the port could be found.
+     */
+    private bool parsePort(const char[] port) pure nothrow @safe @nogc
+    {
+        ptrdiff_t i = 1;
+        float lPort = 0;
+
+        for (; i < port.length && port[i].isDigit() && i <= 6; ++i)
+        {
+            lPort += (port[i] - '0') / cast(float) (10 ^^ (i - 1));
+        }
+        if (i != 1 && (i == port.length || port[i] == '/'))
+        {
+            lPort *= 10 ^^ (i - 2);
+            if (lPort > ushort.max)
+            {
+                return false;
+            }
+            this.port = cast(ushort) lPort;
+            return true;
+        }
+        return false;
+    }
+}
+
+///
+@nogc unittest
+{
+    auto u = URL("example.org");
+    assert(u.path == "example.org"); 
+
+    u = URL("relative/path");
+    assert(u.path == "relative/path"); 
+
+    // Host and scheme
+    u = URL("https://example.org");
+    assert(u.scheme == "https");
+    assert(u.host == "example.org");
+    assert(u.path is null);
+    assert(u.port == 0);
+    assert(u.fragment is null);
+
+    // With user and port and path
+    u = URL("https://hilary:putnam@example.org:443/foo/bar");
+    assert(u.scheme == "https");
+    assert(u.host == "example.org");
+    assert(u.path == "/foo/bar");
+    assert(u.port == 443);
+    assert(u.user == "hilary");
+    assert(u.pass == "putnam");
+    assert(u.fragment is null);
+
+    // With query string
+    u = URL("https://example.org/?login=true");
+    assert(u.scheme == "https");
+    assert(u.host == "example.org");
+    assert(u.path == "/");
+    assert(u.query == "login=true");
+    assert(u.fragment is null);
+
+    // With query string and fragment
+    u = URL("https://example.org/?login=false#label");
+    assert(u.scheme == "https");
+    assert(u.host == "example.org");
+    assert(u.path == "/");
+    assert(u.query == "login=false");
+    assert(u.fragment == "label");
+
+    u = URL("redis://root:password@localhost:2201/path?query=value#fragment");
+    assert(u.scheme == "redis");
+    assert(u.user == "root");
+    assert(u.pass == "password");
+    assert(u.host == "localhost");
+    assert(u.port == 2201);
+    assert(u.path == "/path");
+    assert(u.query == "query=value");
+    assert(u.fragment == "fragment");
+}
+
+private @nogc unittest
+{
+    auto u = URL("127.0.0.1");
+    assert(u.path == "127.0.0.1");
+
+    u = URL("http://127.0.0.1");
+    assert(u.scheme == "http");
+    assert(u.host == "127.0.0.1");
+
+    u = URL("http://127.0.0.1:9000");
+    assert(u.scheme == "http");
+    assert(u.host == "127.0.0.1");
+    assert(u.port == 9000);
+
+    u = URL("127.0.0.1:80");
+    assert(u.host == "127.0.0.1");
+    assert(u.port == 80);
+    assert(u.path is null);
+
+    u = URL("//example.net");
+    assert(u.host == "example.net");
+    assert(u.scheme is null);
+
+    u = URL("//example.net?q=before:after");
+    assert(u.host == "example.net");
+    assert(u.query == "q=before:after");
+
+    u = URL("localhost:8080");
+    assert(u.host == "localhost");
+    assert(u.port == 8080);
+    assert(u.path is null);
+
+    u = URL("ftp:");
+    assert(u.scheme == "ftp");
+
+    u = URL("file:///C:\\Users");
+    assert(u.scheme == "file");
+    assert(u.path == "C:\\Users");
+
+    u = URL("localhost:66000");
+    assert(u.scheme == "localhost");
+    assert(u.path == "66000");
+
+    u = URL("file:///home/");
+    assert(u.scheme == "file");
+    assert(u.path == "/home/");
+
+    u = URL("file:///home/?q=asdf");
+    assert(u.scheme == "file");
+    assert(u.path == "/home/");
+    assert(u.query == "q=asdf");
+
+    u = URL("http://secret@example.org");
+    assert(u.scheme == "http");
+    assert(u.host == "example.org");
+    assert(u.user == "secret");
+
+    u = URL("h_tp://:80");
+    assert(u.path == "h_tp://:80");
+    assert(u.port == 0);
+
+    u = URL("zlib:/home/user/file.gz");
+    assert(u.scheme == "zlib");
+    assert(u.path == "/home/user/file.gz");
+
+    u = URL("h_tp:asdf");
+    assert(u.path == "h_tp:asdf");
+}
+
+private @nogc unittest
+{
+    URIException exception;
+    try
+    {
+        auto u = URL("http://:80");
+    }
+    catch (URIException e)
+    {
+        exception = e;
+    }
+    assert(exception !is null);
+    defaultAllocator.dispose(exception);
+}
+
+private @nogc unittest
+{
+    URIException exception;
+    try
+    {
+        auto u = URL(":80");
+    }
+    catch (URIException e)
+    {
+        exception = e;
+    }
+    assert(exception !is null);
+    defaultAllocator.dispose(exception);
+}
+
+private @nogc unittest
+{
+    URIException exception;
+    try
+    {
+        auto u = URL("http://user1:pass1@user2:pass2@example.org");
+    }
+    catch (URIException e)
+    {
+        exception = e;
+    }
+    assert(exception !is null);
+    defaultAllocator.dispose(exception);
+}
+
+private @nogc unittest
+{
+    URIException exception;
+    try
+    {
+        auto u = URL("http://blah.com:port");
+    }
+    catch (URIException e)
+    {
+        exception = e;
+    }
+    assert(exception !is null);
+    defaultAllocator.dispose(exception);
+}
+
+private @nogc unittest
+{
+    URIException exception;
+    try
+    {
+        auto u = URL("http://blah.com:66000");
+    }
+    catch (URIException e)
+    {
+        exception = e;
+    }
+    assert(exception !is null);
+    defaultAllocator.dispose(exception);
+}
+
+// Issue 254: https://issues.caraus.io/issues/254.
+private @system @nogc unittest
+{
+    auto u = URL("ftp://");
+    assert(u.scheme == "ftp");
+}
+
+/**
+ * Attempts to parse an URL from a string and returns the specified component
+ * of the URL or $(D_PSYMBOL URL) if no component is specified.
+ *
+ * Params:
+ *  T      = "scheme", "host", "port", "user", "pass", "path", "query",
+ *           "fragment".
+ *  source = The string containing the URL.
+ *
+ * Returns: Requested URL component.
+ */
+auto parseURL(string T)(const char[] source)
+if (T == "scheme"
+ || T == "host"
+ || T == "user"
+ || T == "pass"
+ || T == "path"
+ || T == "query"
+ || T == "fragment"
+ || T == "port")
+{
+    auto ret = URL(source);
+    return mixin("ret." ~ T);
+}
+
+/// Ditto.
+URL parseURL(const char[] source) @nogc
+{
+    return URL(source);
+}
+
+///
+@nogc unittest
+{
+    auto u = parseURL("http://example.org:5326");
+    assert(u.scheme == parseURL!"scheme"("http://example.org:5326"));
+    assert(u.host == parseURL!"host"("http://example.org:5326"));
+    assert(u.user == parseURL!"user"("http://example.org:5326"));
+    assert(u.pass == parseURL!"pass"("http://example.org:5326"));
+    assert(u.path == parseURL!"path"("http://example.org:5326"));
+    assert(u.query == parseURL!"query"("http://example.org:5326"));
+    assert(u.fragment == parseURL!"fragment"("http://example.org:5326"));
+    assert(u.port == parseURL!"port"("http://example.org:5326"));
+}

source/tanya/network/package.d

@@ -0,0 +1,15 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Network programming.
+ *
+ * Copyright: Eugene Wissner 2016-2017.
+ * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
+ *                  Mozilla Public License, v. 2.0).
+ * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
+ */
+module tanya.network;
+
+public import tanya.network.socket;

source/tanya/network/socket.d

@@ -3,22 +3,25 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 /**
- * Copyright: Eugene Wissner 2016.
+ * Low-level socket programming.
+ *
+ * Copyright: Eugene Wissner 2016-2017.
  * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
  *                  Mozilla Public License, v. 2.0).
  * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
  */
 module tanya.network.socket;
 
-import tanya.memory;
 import core.stdc.errno;
 import core.time;
 import std.algorithm.comparison;
-import std.algorithm.searching;
-public import std.socket : socket_t, Linger, SocketOptionLevel, SocketOption,
-                           SocketType, AddressFamily, AddressInfo;
+public import std.socket : SocketOptionLevel, SocketOption;
 import std.traits;
 import std.typecons;
+import tanya.memory;
+
+/// Value returned by socket operations on error.
+enum int socketError = -1;
 
 version (Posix)
 {
@@ -30,7 +33,12 @@ version (Posix)
     import core.sys.posix.sys.time;
     import core.sys.posix.unistd;
 
-	private enum SOCKET_ERROR = -1;
+    enum SocketType : int
+    {
+        init = -1,
+    }
+
+    private alias LingerField = int;
 }
 else version (Windows)
 {
@@ -41,16 +49,23 @@ else version (Windows)
     import core.sys.windows.windef;
     import core.sys.windows.winsock2;
 
+    enum SocketType : size_t
+    {
+        init = ~0,
+    }
+
+    private alias LingerField = ushort;
+
     enum : uint
     {
         IOC_UNIX     = 0x00000000,
         IOC_WS2      = 0x08000000,
         IOC_PROTOCOL = 0x10000000,
-		IOC_VOID     = 0x20000000,         /// No parameters.
-		IOC_OUT      = 0x40000000,         /// Copy parameters back.
-		IOC_IN       = 0x80000000,         /// Copy parameters into.
+        IOC_VOID     = 0x20000000,         // No parameters.
+        IOC_OUT      = 0x40000000,         // Copy parameters back.
+        IOC_IN       = 0x80000000,         // Copy parameters into.
         IOC_VENDOR   = 0x18000000,
-		IOC_INOUT    = (IOC_IN | IOC_OUT), /// Copy parameter into and get back.
+        IOC_INOUT    = (IOC_IN | IOC_OUT), // Copy parameter into and get back.
     }
 
     template _WSAIO(int x, int y)
@@ -181,19 +196,26 @@ else version (Windows)
                                                     LPINT,
                                                     SOCKADDR**,
                                                     LPINT);
-	const GUID WSAID_GETACCEPTEXSOCKADDRS = {0xb5367df2,0xcbac,0x11cf,[0x95,0xca,0x00,0x80,0x5f,0x48,0xa1,0x92]};
+    const GUID WSAID_GETACCEPTEXSOCKADDRS = {
+        0xb5367df2, 0xcbac, 0x11cf,
+        [ 0x95, 0xca, 0x00, 0x80, 0x5f, 0x48, 0xa1, 0x92 ],
+    };
 
-	struct WSABUF {
+    struct WSABUF
+    {
         ULONG len;
         CHAR* buf;
     }
     alias WSABUF* LPWSABUF;
 
-	struct WSAOVERLAPPED {
+    struct WSAOVERLAPPED
+    {
         ULONG_PTR Internal;
         ULONG_PTR InternalHigh;
-		union {
-			struct {
+        union
+        {
+            struct
+            {
                 DWORD Offset;
                 DWORD OffsetHigh;
             }
@@ -217,36 +239,13 @@ else version (Windows)
         private WSABUF buffer;
     }
 
-	/**
-	 * Socket returned if a connection has been established.
-	 */
     class OverlappedConnectedSocket : ConnectedSocket
     {
-		/**
-		 * Create a socket.
-		 *
-		 * Params:
-		 *     handle   = Socket handle.
-		 *     af       = Address family.
-		 */
-		this(socket_t handle, AddressFamily af) @nogc
+        this(SocketType handle, AddressFamily af) @nogc
         {
             super(handle, af);
         }
 
-		/**
-		 * Begins to asynchronously receive data from a connected socket.
-		 *
-		 * Params:
-		 *     buffer     = Storage location for the received data.
-		 *     flags      = Flags.
-		 *     overlapped = Unique operation identifier.
-		 *
-		 * Returns: $(D_KEYWORD true) if the operation could be finished synchronously.
-		 *          $(D_KEYWORD false) otherwise.
-		 *
-		 * Throws: $(D_PSYMBOL SocketException) if unable to receive.
-		 */
         bool beginReceive(ubyte[] buffer,
                           SocketState overlapped,
                           Flags flags = Flags(Flag.none)) @nogc @trusted
@@ -266,23 +265,13 @@ else version (Windows)
                                   &overlapped.overlapped,
                                   NULL);
 
-			if (result == SOCKET_ERROR && !wouldHaveBlocked)
+            if (result == socketError && !wouldHaveBlocked)
             {
                 throw defaultAllocator.make!SocketException("Unable to receive");
             }
             return result == 0;
         }
 
-		/**
-		 * Ends a pending asynchronous read.
-		 *
-		 * Params
-		 *     overlapped = Unique operation identifier.
-		 *
-		 * Returns: Number of bytes received.
-		 *
-		 * Throws: $(D_PSYMBOL SocketException) if unable to receive.
-		 */
         int endReceive(SocketState overlapped) @nogc @trusted
         out (count)
         {
@@ -307,19 +296,6 @@ else version (Windows)
             return lpNumber;
         }
 
-		/**
-		 * Sends data asynchronously to a connected socket.
-		 *
-		 * Params:
-		 *     buffer     = Data to be sent.
-		 *     flags      = Flags.
-		 *     overlapped = Unique operation identifier.
-		 *
-		 * Returns: $(D_KEYWORD true) if the operation could be finished synchronously.
-		 *          $(D_KEYWORD false) otherwise.
-		 *
-		 * Throws: $(D_PSYMBOL SocketException) if unable to send.
-		 */
         bool beginSend(ubyte[] buffer,
                        SocketState overlapped,
                        Flags flags = Flags(Flag.none)) @nogc @trusted
@@ -337,7 +313,7 @@ else version (Windows)
                                   &overlapped.overlapped,
                                   NULL);
 
-			if (result == SOCKET_ERROR && !wouldHaveBlocked)
+            if (result == socketError && !wouldHaveBlocked)
             {
                 disconnected_ = true;
                 throw defaultAllocator.make!SocketException("Unable to send");
@@ -345,16 +321,6 @@ else version (Windows)
             return result == 0;
         }
 
-		/**
-		 * Ends a pending asynchronous send.
-		 *
-		 * Params
-		 *     overlapped = Unique operation identifier.
-		 *
-		 * Returns: Number of bytes sent.
-		 *
-		 * Throws: $(D_PSYMBOL SocketException) if unable to receive.
-		*/
         int endSend(SocketState overlapped) @nogc @trusted
         out (count)
         {
@@ -378,17 +344,9 @@ else version (Windows)
 
     class OverlappedStreamSocket : StreamSocket
     {
-		/// Accept extension function pointer.
+        // Accept extension function pointer.
         package LPFN_ACCEPTEX acceptExtension;
 
-		/**
-		 * Create a socket.
-		 *
-		 * Params:
-		 *     af = Address family.
-		 *
-		 * Throws: $(D_PSYMBOL SocketException) on errors.
-		 */
         this(AddressFamily af) @nogc @trusted
         {
             super(af);
@@ -410,28 +368,17 @@ else version (Windows)
                                    &dwBytes,
                                    NULL,
                                    NULL);
-			if (!result == SOCKET_ERROR)
+            if (!result == socketError)
             {
                 throw make!SocketException(defaultAllocator,
                                            "Unable to retrieve an accept extension function pointer");
             }
         }
 
-		/**
-		 * Begins an asynchronous operation to accept an incoming connection attempt.
-		 *
-		 * Params:
-		 *     overlapped = Unique operation identifier.
-		 *
-		 * Returns: $(D_KEYWORD true) if the operation could be finished synchronously.
-		 *          $(D_KEYWORD false) otherwise.
-		 *
-		 * Throws: $(D_PSYMBOL SocketException) on accept errors.
-		 */
         bool beginAccept(SocketState overlapped) @nogc @trusted
         {
-			auto socket = cast(socket_t) socket(addressFamily, SOCK_STREAM, 0);
-			if (socket == socket_t.init)
+            auto socket = cast(SocketType) socket(addressFamily, 1, 0);
+            if (socket == SocketType.init)
             {
                 throw defaultAllocator.make!SocketException("Unable to create socket");
             }
@@ -443,7 +390,7 @@ else version (Windows)
             overlapped.handle = cast(HANDLE) socket;
             overlapped.event = OverlappedSocketEvent.accept;
 
-			immutable len = (sockaddr_in.sizeof + 16) * 2;
+            const len = (sockaddr_in.sizeof + 16) * 2;
             overlapped.buffer.len = len;
             overlapped.buffer.buf = cast(char*) defaultAllocator.allocate(len).ptr;
 
@@ -463,6 +410,139 @@ else version (Windows)
             return result == TRUE;
         }
 
+        OverlappedConnectedSocket endAccept(SocketState overlapped)
+        @nogc @trusted
+        {
+            scope (exit)
+            {
+                defaultAllocator.dispose(overlapped.buffer.buf[0 .. overlapped.buffer.len]);
+            }
+            auto socket = make!OverlappedConnectedSocket(defaultAllocator,
+                                                         cast(SocketType) overlapped.handle,
+                                                         addressFamily);
+            scope (failure)
+            {
+                defaultAllocator.dispose(socket);
+            }
+            socket.setOption(SocketOptionLevel.SOCKET,
+                             cast(SocketOption) SO_UPDATE_ACCEPT_CONTEXT,
+                             cast(size_t) handle);
+            return socket;
+        }
+    }
+}
+else version (D_Ddoc)
+{
+    /// Native socket representation type.
+    enum SocketType;
+
+    /**
+     * Socket returned if a connection has been established.
+     *
+     * Note: Available only on Windows.
+     */
+    class OverlappedConnectedSocket : ConnectedSocket
+    {
+        /**
+         * Create a socket.
+         *
+         * Params:
+         *  handle = Socket handle.
+         *  af     = Address family.
+         */
+        this(SocketType handle, AddressFamily af) @nogc;
+
+        /**
+         * Begins to asynchronously receive data from a connected socket.
+         *
+         * Params:
+         *  buffer     = Storage location for the received data.
+         *  flags      = Flags.
+         *  overlapped = Unique operation identifier.
+         *
+         * Returns: $(D_KEYWORD true) if the operation could be finished synchronously.
+         *          $(D_KEYWORD false) otherwise.
+         *
+         * Throws: $(D_PSYMBOL SocketException) if unable to receive.
+         */
+        bool beginReceive(ubyte[] buffer,
+                          SocketState overlapped,
+                          Flags flags = Flags(Flag.none)) @nogc @trusted;
+
+        /**
+         * Ends a pending asynchronous read.
+         *
+         * Params:
+         *  overlapped = Unique operation identifier.
+         *
+         * Returns: Number of bytes received.
+         *
+         * Throws: $(D_PSYMBOL SocketException) if unable to receive.
+         *
+         * Postcondition: $(D_INLINECODE result >= 0).
+         */
+        int endReceive(SocketState overlapped) @nogc @trusted;
+
+        /**
+         * Sends data asynchronously to a connected socket.
+         *
+         * Params:
+         *  buffer     = Data to be sent.
+         *  flags      = Flags.
+         *  overlapped = Unique operation identifier.
+         *
+         * Returns: $(D_KEYWORD true) if the operation could be finished synchronously.
+         *          $(D_KEYWORD false) otherwise.
+         *
+         * Throws: $(D_PSYMBOL SocketException) if unable to send.
+         */
+        bool beginSend(ubyte[] buffer,
+                       SocketState overlapped,
+                       Flags flags = Flags(Flag.none)) @nogc @trusted;
+
+        /**
+         * Ends a pending asynchronous send.
+         *
+         * Params:
+         *  overlapped = Unique operation identifier.
+         *
+         * Returns: Number of bytes sent.
+         *
+         * Throws: $(D_PSYMBOL SocketException) if unable to receive.
+         *
+         * Postcondition: $(D_INLINECODE result >= 0).
+        */
+        int endSend(SocketState overlapped) @nogc @trusted;
+    }
+
+    /**
+     * Windows stream socket overlapped I/O.
+     */
+    class OverlappedStreamSocket : StreamSocket
+    {
+        /**
+         * Create a socket.
+         *
+         * Params:
+         *  af = Address family.
+         *
+         * Throws: $(D_PSYMBOL SocketException) on errors.
+         */
+        this(AddressFamily af) @nogc @trusted;
+
+        /**
+         * Begins an asynchronous operation to accept an incoming connection attempt.
+         *
+         * Params:
+         *  overlapped = Unique operation identifier.
+         *
+         * Returns: $(D_KEYWORD true) if the operation could be finished synchronously.
+         *          $(D_KEYWORD false) otherwise.
+         *
+         * Throws: $(D_PSYMBOL SocketException) on accept errors.
+         */
+        bool beginAccept(SocketState overlapped) @nogc @trusted;
+
         /**
          * Asynchronously accepts an incoming connection attempt and creates a
          * new socket to handle remote host communication.
@@ -474,24 +554,116 @@ else version (Windows)
          *
          * Throws: $(D_PSYMBOL SocketException) if unable to accept.
          */
-		OverlappedConnectedSocket endAccept(SocketState overlapped) @nogc @trusted
-		{
-			scope (exit)
-			{
-				defaultAllocator.dispose(overlapped.buffer.buf[0 .. overlapped.buffer.len]);
+        OverlappedConnectedSocket endAccept(SocketState overlapped)
+        @nogc @trusted;
     }
-			auto socket = make!OverlappedConnectedSocket(defaultAllocator,
-			                                             cast(socket_t) overlapped.handle,
-			                                             addressFamily);
-			scope (failure)
+}
+
+/**
+ * Socket option that specifies what should happen when the socket that
+ * promises reliable delivery still has untransmitted messages when
+ * it is closed.
+ */
+struct Linger
+{
+    /// If nonzero, $(D_PSYMBOL close) and $(D_PSYMBOL shutdown) block until
+    /// the data are transmitted or the timeout period has expired.
+    LingerField l_onoff;
+
+    /// Time, in seconds to wait before any buffered data to be sent is
+    /// discarded.
+    LingerField l_linger;
+
+    /**
+     * If $(D_PARAM timeout) is `0`, linger is disabled, otherwise enables the
+     * linger and sets the timeout.
+     *
+     * Params:
+     *  timeout = Timeout, in seconds.
+     */
+    this(const ushort timeout)
     {
-				defaultAllocator.dispose(socket);
+        time = timeout;
     }
-			socket.setOption(SocketOptionLevel.SOCKET,
-			                 cast(SocketOption) SO_UPDATE_ACCEPT_CONTEXT,
-			                 cast(size_t) handle);
-			return socket;
+
+    ///
+    unittest
+    {
+        {
+            auto linger = Linger(5);
+            assert(linger.enabled);
+            assert(linger.time == 5);
         }
+        {
+            auto linger = Linger(0);
+            assert(!linger.enabled);
+        }
+        { // Default constructor.
+            Linger linger;
+            assert(!linger.enabled);
+        }
+    }
+
+    /**
+     * System dependent constructor.
+     *
+     * Params:
+     *  l_onoff  = $(D_PSYMBOL l_onoff) value.
+     *  l_linger = $(D_PSYMBOL l_linger) value.
+     */
+    this(LingerField l_onoff, LingerField l_linger)
+    {
+        this.l_onoff = l_onoff;
+        this.l_linger = l_linger;
+    }
+
+    ///
+    unittest
+    {
+        auto linger = Linger(1, 5);
+        assert(linger.l_onoff == 1);
+        assert(linger.l_linger == 5);
+    }
+
+    /**
+     * Params:
+     *  value = Whether to linger after the socket is closed.
+     *
+     * See_Also: $(D_PSYMBOL time).
+     */
+    @property enabled(const bool value) pure nothrow @safe @nogc
+    {
+        this.l_onoff = value;
+    }
+
+    /**
+     * Returns: Whether to linger after the socket is closed.
+     */
+    @property bool enabled() const pure nothrow @safe @nogc
+    {
+        return this.l_onoff != 0;
+    }
+
+    /**
+     * Returns: Timeout period, in seconds, to wait before closing the socket
+     *          if the $(D_PSYMBOL Linger) is $(D_PSYMBOL enabled).
+     */
+    @property ushort time() const pure nothrow @safe @nogc
+    {
+        return this.l_linger & ushort.max;
+    }
+
+    /**
+     *  Sets timeout period, to wait before closing the socket if the
+     *  $(D_PSYMBOL Linger) is $(D_PSYMBOL enabled), ignored otherwise.
+     *
+     * Params:
+     *  timeout = Timeout period, in seconds.
+     */
+    @property void time(const ushort timeout) pure nothrow @safe @nogc
+    {
+        this.l_onoff = timeout > 0;
+        this.l_linger = timeout;
     }
 }
 
@@ -523,7 +695,7 @@ else version (DragonFlyBSD)
 
 version (MacBSD)
 {
-	enum ESOCKTNOSUPPORT = 44; /// Socket type not suppoted.
+    enum ESOCKTNOSUPPORT = 44; // Socket type not suppoted.
 }
 
 private immutable
@@ -550,12 +722,32 @@ shared static this()
     }
 }
 
+/**
+ * $(D_PSYMBOL AddressFamily) specifies a communication domain; this selects
+ * the protocol family which will be used for communication.
+ */
+enum AddressFamily : int
+{
+    unspec    = 0,     /// Unspecified.
+    local     = 1,     /// Local to host (pipes and file-domain).
+    unix      = local, /// POSIX name for PF_LOCAL.
+    inet      = 2,     /// IP protocol family.
+    ax25      = 3,     /// Amateur Radio AX.25.
+    ipx       = 4,     /// Novell Internet Protocol.
+    appletalk = 5,     /// Appletalk DDP.
+    netrom    = 6,     /// Amateur radio NetROM.
+    bridge    = 7,     /// Multiprotocol bridge.
+    atmpvc    = 8,     /// ATM PVCs.
+    x25       = 9,     /// Reserved for X.25 project.
+    inet6     = 10,    /// IP version 6.
+}
+
 /**
  * Error codes for $(D_PSYMBOL Socket).
  */
 enum SocketError : int
 {
-	/// Unknown error
+    /// Unknown error.
     unknown                = 0,
     /// Firewall rules forbid connection.
     accessDenied           = EPERM,
@@ -585,12 +777,12 @@ enum SocketError : int
 
 /**
  * $(D_PSYMBOL SocketException) should be thrown only if one of the socket functions
- * returns -1 or $(D_PSYMBOL SOCKET_ERROR) and sets $(D_PSYMBOL errno),
- * because $(D_PSYMBOL SocketException) relies on the $(D_PSYMBOL errno) value.
+ * $(D_PSYMBOL socketError) and sets $(D_PSYMBOL errno), because
+ * $(D_PSYMBOL SocketException) relies on the $(D_PSYMBOL errno) value.
  */
 class SocketException : Exception
 {
-	immutable SocketError error = SocketError.unknown;
+    const SocketError error = SocketError.unknown;
 
     /**
      * Params:
@@ -678,16 +870,16 @@ abstract class Socket
     }
 
     /// Socket handle.
-	protected socket_t handle_;
+    protected SocketType handle_;
 
     /// Address family.
     protected AddressFamily family;
 
-	private @property void handle(socket_t handle) @nogc
+    private @property void handle(SocketType handle) @nogc
     in
     {
-		assert(handle != socket_t.init);
-		assert(handle_ == socket_t.init, "Socket handle cannot be changed");
+        assert(handle != SocketType.init);
+        assert(handle_ == SocketType.init, "Socket handle cannot be changed");
     }
     body
     {
@@ -701,7 +893,7 @@ abstract class Socket
         }
     }
 
-	@property inout(socket_t) handle() inout const pure nothrow @safe @nogc
+    @property inout(SocketType) handle() inout const pure nothrow @safe @nogc
     {
         return handle_;
     }
@@ -713,10 +905,10 @@ abstract class Socket
      *  handle = Socket.
      *  af     = Address family.
      */
-	this(socket_t handle, AddressFamily af) @nogc
+    this(SocketType handle, AddressFamily af) @nogc
     in
     {
-		assert(handle != socket_t.init);
+        assert(handle != SocketType.init);
     }
     body
     {
@@ -757,7 +949,7 @@ abstract class Socket
                        cast(int) level,
                        cast(int) option,
                        result.ptr,
-		               &length) == SOCKET_ERROR)
+                       &length) == socketError)
         {
             throw defaultAllocator.make!SocketException("Unable to get socket option");
         }
@@ -769,7 +961,7 @@ abstract class Socket
                   SocketOption option,
                   out size_t result) const @trusted @nogc
     {
-		return getOption(level, option, (&result)[0..1]);
+        return getOption(level, option, (&result)[0 .. 1]);
     }
 
     /// Ditto.
@@ -777,7 +969,7 @@ abstract class Socket
                   SocketOption option,
                   out Linger result) const @trusted @nogc
     {
-		return getOption(level, option, (&result.clinger)[0..1]);
+        return getOption(level, option, (&result)[0 .. 1]);
     }
 
     /// Ditto.
@@ -790,7 +982,7 @@ abstract class Socket
         version (Posix)
         {
             timeval tv;
-			auto ret = getOption(level, option, (&tv)[0..1]);
+            auto ret = getOption(level, option, (&tv)[0 .. 1]);
             result = dur!"seconds"(tv.tv_sec) + dur!"usecs"(tv.tv_usec);
         }
         else version (Windows)
@@ -824,7 +1016,7 @@ abstract class Socket
                        cast(int)level,
                        cast(int)option,
                        value.ptr,
-		               cast(uint) value.length) == SOCKET_ERROR)
+                       cast(uint) value.length) == socketError)
         {
             throw defaultAllocator.make!SocketException("Unable to set socket option");
         }
@@ -834,14 +1026,14 @@ abstract class Socket
     void setOption(SocketOptionLevel level, SocketOption option, size_t value)
     const @trusted @nogc
     {
-		setOption(level, option, (&value)[0..1]);
+        setOption(level, option, (&value)[0 .. 1]);
     }
 
     /// Ditto.
     void setOption(SocketOptionLevel level, SocketOption option, Linger value)
     const @trusted @nogc
     {
-		setOption(level, option, (&value.clinger)[0..1]);
+        setOption(level, option, (&value)[0 .. 1]);
     }
 
     /// Ditto.
@@ -852,7 +1044,7 @@ abstract class Socket
         {
             timeval tv;
             value.split!("seconds", "usecs")(tv.tv_sec, tv.tv_usec);
-			setOption(level, option, (&tv)[0..1]);
+            setOption(level, option, (&tv)[0 .. 1]);
         }
         else version (Windows)
         {
@@ -876,7 +1068,7 @@ abstract class Socket
         }
         else version (Windows)
         {
-			return blocking_;
+            return this.blocking_;
         }
     }
 
@@ -890,12 +1082,12 @@ abstract class Socket
         {
             int fl = fcntl(handle_, F_GETFL, 0);
 
-			if (fl != SOCKET_ERROR)
+            if (fl != socketError)
             {
                 fl = yes ? fl & ~O_NONBLOCK : fl | O_NONBLOCK;
                 fl = fcntl(handle_, F_SETFL, fl);
             }
-			if (fl == SOCKET_ERROR)
+            if (fl == socketError)
             {
                 throw make!SocketException(defaultAllocator,
                                            "Unable to set socket blocking");
@@ -904,12 +1096,12 @@ abstract class Socket
         else version (Windows)
         {
             uint num = !yes;
-			if (ioctlsocket(handle_, FIONBIO, &num) == SOCKET_ERROR)
+            if (ioctlsocket(handle_, FIONBIO, &num) == socketError)
             {
                 throw make!SocketException(defaultAllocator,
                                            "Unable to set socket blocking");
             }
-			blocking_ = yes;
+            this.blocking_ = yes;
         }
     }
 
@@ -961,7 +1153,7 @@ abstract class Socket
         {
             .close(handle_);
         }
-		handle_ = socket_t.init;
+        handle_ = SocketType.init;
     }
 
     /**
@@ -974,7 +1166,7 @@ abstract class Socket
      */
     void listen(int backlog) const @trusted @nogc
     {
-		if (.listen(handle_, backlog) == SOCKET_ERROR)
+        if (.listen(handle_, backlog) == socketError)
         {
             throw defaultAllocator.make!SocketException("Unable to listen on socket");
         }
@@ -1004,10 +1196,14 @@ interface ConnectionOrientedSocket
      */
     enum Flag : int
     {
-		none      = 0,             /// No flags specified
-		outOfBand = MSG_OOB,       /// Out-of-band stream data
-		peek      = MSG_PEEK,      /// Peek at incoming data without removing it from the queue, only for receiving
-		dontRoute = MSG_DONTROUTE, /// Data should not be subject to routing; this flag may be ignored. Only for sending
+        /// No flags specified.
+        none      = 0,
+        /// Out-of-band stream data.
+        outOfBand = MSG_OOB,
+        /// Peek at incoming data without removing it from the queue, only for receiving.
+        peek      = MSG_PEEK,
+        /// Data should not be subject to routing; this flag may be ignored. Only for sending.
+        dontRoute = MSG_DONTROUTE,
     }
 
     alias Flags = BitFlags!Flag;
@@ -1023,8 +1219,8 @@ class StreamSocket : Socket, ConnectionOrientedSocket
      */
     this(AddressFamily af) @trusted @nogc
     {
-		auto handle = cast(socket_t) socket(af, SOCK_STREAM, 0);
-		if (handle == socket_t.init)
+        auto handle = cast(SocketType) socket(af, 1, 0);
+        if (handle == SocketType.init)
         {
             throw defaultAllocator.make!SocketException("Unable to create socket");
         }
@@ -1041,7 +1237,7 @@ class StreamSocket : Socket, ConnectionOrientedSocket
      */
     void bind(Address address) const @trusted @nogc
     {
-		if (.bind(handle_, address.name, address.length) == SOCKET_ERROR)
+        if (.bind(handle_, address.name, address.length) == socketError)
         {
             throw defaultAllocator.make!SocketException("Unable to bind socket");
         }
@@ -1060,7 +1256,7 @@ class StreamSocket : Socket, ConnectionOrientedSocket
      */
     ConnectedSocket accept() @trusted @nogc
     {
-		socket_t sock;
+        SocketType sock;
 
         version (linux)
         {
@@ -1069,14 +1265,14 @@ class StreamSocket : Socket, ConnectionOrientedSocket
             {
                 flags |= SOCK_NONBLOCK;
             }
-			sock = cast(socket_t).accept4(handle_, null, null, flags);
+            sock = cast(SocketType).accept4(handle_, null, null, flags);
         }
         else
         {
-			sock = cast(socket_t).accept(handle_, null, null);
+            sock = cast(SocketType).accept(handle_, null, null);
         }
 
-		if (sock == socket_t.init)
+        if (sock == SocketType.init)
         {
             if (wouldHaveBlocked())
             {
@@ -1141,7 +1337,7 @@ class ConnectedSocket : Socket, ConnectionOrientedSocket
      *  handle = Socket.
      *  af     = Address family.
      */
-	this(socket_t handle, AddressFamily af) @nogc
+    this(SocketType handle, AddressFamily af) @nogc
     {
         super(handle, af);
     }
@@ -1190,7 +1386,7 @@ class ConnectedSocket : Socket, ConnectionOrientedSocket
         {
             disconnected_ = true;
         }
-		else if (ret == SOCKET_ERROR)
+        else if (ret == socketError)
         {
             if (wouldHaveBlocked())
             {
@@ -1227,7 +1423,7 @@ class ConnectedSocket : Socket, ConnectionOrientedSocket
         }
 
         sent = .send(handle_, buf.ptr, capToMaxBuffer(buf.length), sendFlags);
-		if (sent != SOCKET_ERROR)
+        if (sent != socketError)
         {
             return sent;
         }
@@ -1267,14 +1463,11 @@ class InternetAddress : Address
         /// Internal internet address representation.
         protected sockaddr_storage storage;
     }
-	immutable ushort port_;
+    const ushort port_;
 
-	enum
-	{
-		anyPort = 0,
-	}
+    enum ushort anyPort = 0;
 
-	this(in string host, ushort port = anyPort) @nogc
+    this(string host, const ushort port = anyPort) @nogc
     {
         if (getaddrinfoPointer is null || freeaddrinfoPointer is null)
         {
@@ -1282,11 +1475,11 @@ class InternetAddress : Address
                                        "Address info lookup is not available on this system");
         }
         addrinfo* ai_res;
-		port_ = port;
+        this.port_ = port;
 
         // Make C-string from host.
         auto node = cast(char[]) allocator.allocate(host.length + 1);
-		node[0.. $ - 1] = host;
+        node[0 .. $ - 1] = host;
         node[$ - 1] = '\0';
         scope (exit)
         {
@@ -1298,18 +1491,19 @@ class InternetAddress : Address
         const(char)* servicePointer;
         if (port)
         {
+            ushort originalPort = port;
             ushort start;
             for (ushort j = 10, i = 4; i > 0; j *= 10, --i)
             {
-				ushort rest = port % 10;
+                ushort rest = originalPort % 10;
                 if (rest != 0)
                 {
                     service[i] = cast(char) (rest + '0');
                     start = i;
                 }
-				port /= 10;
+                originalPort /= 10;
             }
-			servicePointer = service[start..$].ptr;
+            servicePointer = service[start .. $].ptr;
         }
 
         auto ret = getaddrinfoPointer(node.ptr, servicePointer, null, &ai_res);
@@ -1327,12 +1521,23 @@ class InternetAddress : Address
         {
             *dp = *sp;
         }
-		if (ai_res.ai_family != AddressFamily.INET && ai_res.ai_family != AddressFamily.INET6)
+        if (ai_res.ai_family != AddressFamily.inet && ai_res.ai_family != AddressFamily.inet6)
         {
             throw defaultAllocator.make!SocketException("Wrong address family");
         }
     }
 
+    ///
+    unittest
+    {
+        auto address = defaultAllocator.make!InternetAddress("127.0.0.1");
+        assert(address.port == InternetAddress.anyPort);
+        assert(address.name !is null);
+        assert(address.family == AddressFamily.inet);
+
+        defaultAllocator.dispose(address);
+    }
+
     /**
      * Returns: Pointer to underlying $(D_PSYMBOL sockaddr) structure.
      */
@@ -1349,9 +1554,9 @@ class InternetAddress : Address
         // FreeBSD wants to know the exact length of the address on bind.
         switch (family)
         {
-			case AddressFamily.INET:
+            case AddressFamily.inet:
                 return sockaddr_in.sizeof;
-			case AddressFamily.INET6:
+            case AddressFamily.inet6:
                 return sockaddr_in6.sizeof;
             default:
                 assert(false);
@@ -1370,6 +1575,15 @@ class InternetAddress : Address
     {
         return port_;
     }
+
+    ///
+    unittest
+    {
+        auto address = defaultAllocator.make!InternetAddress("127.0.0.1",
+                                                             cast(ushort) 1234);
+        assert(address.port == 1234);
+        defaultAllocator.dispose(address);
+    }
 }
 
 /**

source/tanya/os/error.d

@@ -0,0 +1,337 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * This module provides a portable way of using operating system error codes.
+ *
+ * Copyright: Eugene Wissner 2017.
+ * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
+ *                  Mozilla Public License, v. 2.0).
+ * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
+ */
+module tanya.os.error;
+
+// Socket API error.
+private template SAError(int posix, int wsa = posix)
+{
+    version (Windows)
+    {
+        enum SAError = 10000 + wsa;
+    }
+    else
+    {
+        alias SAError = posix;
+    }
+}
+
+// Error for Windows and Posix separately.
+private template NativeError(int posix, int win)
+{
+    version (Windows)
+    {
+        alias NativeError = win;
+    }
+    else
+    {
+        alias NativeError = posix;
+    }
+}
+
+version (Windows)
+{
+    private enum eProtocolError = -71;
+}
+else version (OpenBSD)
+{
+    private enum eProtocolError = -71;
+}
+else
+{
+    private enum eProtocolError = 71;
+}
+
+/**
+ * System error code.
+ */
+struct ErrorCode
+{
+    /**
+     * Error code numbers.
+     */
+    enum ErrorNo : int
+    {
+        /// The operation completed successfully.
+        success                   = 0,
+
+        /// Operation not permitted.
+        noPermission              = NativeError!(1, 5),
+
+        /// Interrupted system call.
+        interrupted               = SAError!4,
+
+        /// Bad file descriptor.
+        badDescriptor             = SAError!9,
+
+        /// An operation on a non-blocking socket would block.
+        wouldBlock                = SAError!(11, 35),
+
+        /// Out of memory.
+        noMemory                  = NativeError!(12, 14),
+
+        /// Access denied.
+        accessDenied              = SAError!13,
+
+        /// An invalid pointer address detected.
+        fault                     = SAError!14,
+
+        /// No such device.
+        noSuchDevice              = NativeError!(19, 20),
+
+        /// An invalid argument was supplied.
+        invalidArgument           = SAError!22,
+
+        /// The limit on the number of open file descriptors.
+        tooManyDescriptors        = NativeError!(23, 331),
+
+        /// The limit on the number of open file descriptors.
+        noDescriptors             = SAError!24,
+
+        /// Broken pipe.
+        brokenPipe                = NativeError!(32, 109),
+
+        /// The name was too long.
+        nameTooLong               = SAError!(36, 63),
+
+        /// A socket operation was attempted on a non-socket.
+        notSocket                 = SAError!(88, 38),
+
+        /// Protocol error.
+        protocolError             = eProtocolError,
+
+        /// Message too long.
+        messageTooLong            = SAError!(90, 40),
+
+        /// Wrong protocol type for socket.
+        wrongProtocolType         = SAError!(91, 41),
+
+        /// Protocol not available.
+        noProtocolOption          = SAError!(92, 42),
+
+        /// The protocol is not implemented orR has not been configured.
+        protocolNotSupported      = SAError!(93, 43),
+
+        /// The support for the specified socket type does not exist in this
+        /// address family.
+        socketNotSupported        = SAError!(94, 44),
+
+        /// The address family is no supported by the protocol family.
+        operationNotSupported     = SAError!(95, 45),
+
+        /// Address family specified is not supported.
+        addressFamilyNotSupported = SAError!(97, 47),
+
+        /// Address already in use.
+        addressInUse              = SAError!(98, 48),
+
+        /// The network is not available.
+        networkDown               = SAError!(100, 50),
+
+        /// No route to host.
+        networkUnreachable        = SAError!(101, 51),
+
+        /// Network dropped connection because of reset.
+        networkReset              = SAError!(102, 52),
+
+        /// The connection has been aborted.
+        connectionAborted         = SAError!(103, 53),
+
+        /// Connection reset by peer.
+        connectionReset           = SAError!(104, 54),
+
+        /// No free buffer space is available for a socket operation.
+        noBufferSpace             = SAError!(105, 55),
+
+        /// Transport endpoint is already connected.
+        alreadyConnected          = SAError!(106, 56),
+
+        /// Transport endpoint is not connected.
+        notConnected              = SAError!(107, 57),
+
+        /// Cannot send after transport endpoint shutdown.
+        shutdown                  = SAError!(108, 58),
+
+        /// The connection attempt timed out, or the connected host has failed
+        /// to respond.
+        timedOut                  = SAError!(110, 60),
+
+        /// Connection refused.
+        connectionRefused         = SAError!(111, 61),
+
+        /// Host is down.
+        hostDown                  = SAError!(112, 64),
+
+        /// No route to host.
+        hostUnreachable           = SAError!(113, 65),
+
+        /// Operation already in progress.
+        alreadyStarted            = SAError!(114, 37),
+
+        /// Operation now in progress.
+        inProgress                = SAError!(115, 36),
+
+        /// Operation cancelled.
+        cancelled                 = SAError!(125, 103),
+    }
+
+    /**
+     * Constructor.
+     *
+     * Params:
+     *  value = Numeric error code.
+     */
+    this(const ErrorNo value) pure nothrow @safe @nogc
+    {
+        this.value_ = value;
+    }
+
+    ///
+    pure nothrow @safe @nogc unittest
+    {
+        ErrorCode ec;
+        assert(ec == ErrorCode.success);
+
+        ec = ErrorCode.fault;
+        assert(ec == ErrorCode.fault);
+    }
+
+    /**
+     * Resets this $(D_PSYMBOL ErrorCode) to default
+     * ($(D_PSYMBOL ErrorCode.success)).
+     */
+    void reset() pure nothrow @safe @nogc
+    {
+        this.value_ = ErrorNo.success;
+    }
+
+    ///
+    pure nothrow @safe @nogc unittest
+    {
+        auto ec = ErrorCode(ErrorCode.fault);
+        assert(ec == ErrorCode.fault);
+
+        ec.reset();
+        assert(ec == ErrorCode.success);
+    }
+
+    /**
+     * Returns: Numeric error code.
+     */
+    ErrorNo opCast(T : ErrorNo)() const
+    {
+        return this.value_;
+    }
+
+    /// Ditto.
+    ErrorNo opCast(T : int)() const
+    {
+        return this.value_;
+    }
+
+    ///
+    pure nothrow @safe @nogc unittest
+    {
+        ErrorCode ec = ErrorCode.fault;
+        auto errorNo = cast(ErrorCode.ErrorNo) ec;
+
+        assert(errorNo == ErrorCode.fault);
+        static assert(is(typeof(cast(int) ec)));
+    }
+
+    /**
+     * Assigns another error code or error code number.
+     *
+     * Params:
+     *  that = Numeric error code.
+     *
+     * Returns: $(D_KEYWORD this).
+     */
+    ref ErrorCode opAssign(const ErrorNo that) pure nothrow @safe @nogc
+    {
+        this.value_ = that;
+        return this;
+    }
+
+    /// Ditto.
+    ref ErrorCode opAssign()(auto ref const ErrorCode that)
+    pure nothrow @safe @nogc
+    {
+        this.value_ = that.value_;
+        return this;
+    }
+
+    ///
+    pure nothrow @safe @nogc unittest
+    {
+        {
+            ErrorCode ec;
+            assert(ec == ErrorCode.success);
+
+            ec = ErrorCode.fault;
+            assert(ec == ErrorCode.fault);
+        }
+        {
+            auto ec1 = ErrorCode(ErrorCode.fault);
+            ErrorCode ec2;
+            assert(ec2 == ErrorCode.success);
+
+            ec2 = ec1;
+            assert(ec1 == ec2);
+        }
+    }
+
+    /**
+     * Equality with another error code or error code number.
+     *
+     * Params:
+     *  that = Numeric error code.
+     *
+     * Returns: Whether $(D_KEYWORD this) and $(D_PARAM that) are equal.
+     */
+    bool opEquals(const ErrorNo that) const pure nothrow @safe @nogc
+    {
+        return this.value_ == that;
+    }
+
+    /// Ditto.
+    bool opEquals()(auto ref const ErrorCode that)
+    const pure nothrow @safe @nogc
+    {
+        return this.value_ == that.value_;
+    }
+
+    ///
+    pure nothrow @safe @nogc unittest
+    {
+        {
+            ErrorCode ec1 = ErrorCode.fault;
+            ErrorCode ec2 = ErrorCode.accessDenied;
+
+            assert(ec1 != ec2);
+            assert(ec1 != ErrorCode.accessDenied);
+            assert(ErrorCode.fault != ec2);
+        }
+        {
+            ErrorCode ec1 = ErrorCode.fault;
+            ErrorCode ec2 = ErrorCode.fault;
+
+            assert(ec1 == ec2);
+            assert(ec1 == ErrorCode.fault);
+            assert(ErrorCode.fault == ec2);
+        }
+    }
+
+    private ErrorNo value_ = ErrorNo.success;
+
+    alias ErrorNo this;
+}

source/tanya/os/package.d

@@ -0,0 +1,16 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * This package provides platform-independent interfaces to operating system
+ * functionality.
+ *
+ * Copyright: Eugene Wissner 2017.
+ * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
+ *                  Mozilla Public License, v. 2.0).
+ * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
+ */
+module tanya.os;
+
+public import tanya.os.error;

source/tanya/typecons.d

@@ -0,0 +1,107 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Type constructors.
+ *
+ * This module contains templates that allow to build new types from the
+ * available ones.
+ *
+ * Copyright: Eugene Wissner 2017.
+ * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
+ *                  Mozilla Public License, v. 2.0).
+ * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
+ */
+module tanya.typecons;
+
+import std.meta;
+
+/**
+ * $(D_PSYMBOL Pair) can store two heterogeneous objects.
+ *
+ * The objects can by accessed by index as $(D_INLINECODE obj[0]) and
+ * $(D_INLINECODE obj[1]) or by optional names (e.g.
+ * $(D_INLINECODE obj.first)).
+ *
+ * $(D_PARAM Specs) contains a list of object types and names. First
+ * comes the object type, then an optional string containing the name.
+ * If you want the object be accessible only by its index (`0` or `1`),
+ * just skip the name.
+ *
+ * Params:
+ *  Specs = Field types and names.
+ */
+template Pair(Specs...)
+{
+    template parseSpecs(int fieldCount, Specs...)
+    {
+        static if (Specs.length == 0)
+        {
+            alias parseSpecs = AliasSeq!();
+        }
+        else static if (is(Specs[0]) && fieldCount < 2)
+        {
+            static if (is(typeof(Specs[1]) == string))
+            {
+                alias parseSpecs
+                    = AliasSeq!(Specs[0],
+                                parseSpecs!(fieldCount + 1, Specs[2 .. $]));
+            }
+            else
+            {
+                alias parseSpecs
+                    = AliasSeq!(Specs[0],
+                                parseSpecs!(fieldCount + 1, Specs[1 .. $]));
+            }
+        }
+        else
+        {
+            static assert(false, "Invalid argument: " ~ Specs[0].stringof);
+        }
+    }
+
+    struct Pair
+    {
+        /// Field types.
+        alias Types = parseSpecs!(0, Specs);
+
+        static assert(Types.length == 2, "Invalid argument count.");
+
+        // Create field aliases.
+        static if (is(typeof(Specs[1]) == string))
+        {
+            mixin("alias " ~ Specs[1] ~ " = expand[0];");
+        }
+        static if (is(typeof(Specs[2]) == string))
+        {
+            mixin("alias " ~ Specs[2] ~ " = expand[1];");
+        }
+        else static if (is(typeof(Specs[3]) == string))
+        {
+            mixin("alias " ~ Specs[3] ~ " = expand[1];");
+        }
+
+        /// Represents the values of the $(D_PSYMBOL Pair) as a list of values.
+        Types expand;
+
+        alias expand this;
+    }
+}
+
+///
+unittest
+{
+    static assert(is(Pair!(int, int)));
+    static assert(!is(Pair!(int, 5)));
+
+    static assert(is(Pair!(int, "first", int)));
+    static assert(is(Pair!(int, "first", int, "second")));
+    static assert(is(Pair!(int, "first", int)));
+
+    static assert(is(Pair!(int, int, "second")));
+    static assert(!is(Pair!("first", int, "second", int)));
+    static assert(!is(Pair!(int, int, int)));
+
+    static assert(!is(Pair!(int, "first")));
+}