tanya/source/tanya/functional.d

72 lines
1.9 KiB
D

/* 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/. */
/**
* Functions that manipulate other functions and their argument lists.
*
* Copyright: Eugene Wissner 2018.
* 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)
* Source: $(LINK2 https://github.com/caraus-ecms/tanya/blob/master/source/tanya/functional.d,
* tanya/functional.d)
*/
module tanya.functional;
import tanya.algorithm.mutation;
import tanya.meta.metafunction;
private template forwardOne(alias arg)
{
static if (__traits(isRef, arg) || __traits(isOut, arg))
{
alias forwardOne = arg;
}
else
{
@property auto forwardOne()
{
return move(arg);
}
}
}
/**
* Forwards its argument list preserving $(D_KEYWORD ref) and $(D_KEYWORD out)
* storage classes.
*
* $(D_PSYMBOL forward) accepts a list of variables or literals. It returns an
* argument list of the same length that can be for example passed to a
* function accepting the arguments of this type.
*
* Params:
* args = Argument list.
*
* Returns: $(D_PARAM args) with their original storage classes.
*/
template forward(args...)
{
static if (args.length == 1)
{
alias forward = forwardOne!(args[0]);
}
else
{
alias forward = Map!(forwardOne, args);
}
}
///
@nogc nothrow pure @safe unittest
{
static assert(is(typeof((int i) { int v = forward!i; })));
static assert(is(typeof((ref int i) { int v = forward!i; })));
static assert(is(typeof({
void f(int i, ref int j, out int k)
{
f(forward!(i, j, k));
}
})));
}