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Add support for enums to format.conv.to. Fix #240

This commit is contained in:
Eugen Wissner 2017-06-23 02:58:46 +02:00
parent a4de1cc754
commit e5f83c22fa
1 changed files with 179 additions and 16 deletions
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195
source/tanya/format/conv.d
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@ -38,7 +38,8 @@ final class ConvException : Exception
/**
* If the source type $(D_PARAM From) and the target type $(D_PARAM To) are
* equal, does nothing.
* equal, does nothing. If $(D_PARAM From) can be implicitly converted to
* $(D_PARAM To), just returns $(D_PARAM from).
*
* Params:
* From = Source type.
@ -56,7 +57,7 @@ template to(To)
}
To to(From)(From from)
if (is(Unqual!To == Unqual!From))
if (is(Unqual!To == Unqual!From) || isNumeric!From && isFloatingPoint!To)
{
return from;
}
@ -78,9 +79,7 @@ private pure nothrow @safe @nogc unittest
/**
* Performs checked conversion from an integral type $(D_PARAM From) to an
* integral type $(D_PARAM To). If the conversion isn't possible (for example
* because $(D_PARAM from) is too small or too large to be represented by
* $(D_PARAM To)), an exception is thrown.
* integral type $(D_PARAM To).
*
* Params:
* From = Source type.
@ -89,10 +88,14 @@ private pure nothrow @safe @nogc unittest
*
* Returns: $(D_PARAM from) converted to $(D_PARAM To).
*
* Throws: $(D_PSYMBOL ConvException).
* 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(To == 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)
@ -254,10 +257,19 @@ private unittest
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. If $(D_PARAM from) is greater than `1` or
* less than `0`, an exception is thrown, `0` results in $(D_KEYWORD false) and
* all other values result in $(D_KEYWORD true).
* Converts a number to a boolean.
*
* Params:
* From = Source type.
@ -267,10 +279,11 @@ private unittest
* Returns: $(D_KEYWORD true) if $(D_INLINECODE from > 0 && from <= 1),
* otherwise $(D_KEYWORD false).
*
* Throws: $(D_PSYMBOL ConvException).
* 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(To == From))
if (isNumeric!From && is(Unqual!To == bool) && !is(Unqual!To == Unqual!From))
{
if (from == 0)
{
@ -289,7 +302,7 @@ if (isNumeric!From && is(Unqual!To == bool) && !is(To == From))
"Positive number overflow");
}
private unittest
private @nogc unittest
{
assert(0.0.to!bool == false);
assert(0.2.to!bool == true);
@ -300,7 +313,7 @@ private unittest
assert(1.to!bool == true);
}
private unittest
private @nogc unittest
{
ConvException exception;
try
@ -315,7 +328,7 @@ private unittest
defaultAllocator.dispose(exception);
}
private unittest
private @nogc unittest
{
ConvException exception;
try
@ -342,7 +355,7 @@ private unittest
* 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(To == From))
if (is(Unqual!From == bool) && isNumeric!To && !is(Unqual!To == Unqual!From))
{
return from;
}
@ -368,3 +381,153 @@ pure nothrow @safe @nogc unittest
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);
}