Merge remote-tracking branch 'retro-retro'

This commit is contained in:
Eugen Wissner 2018-11-06 16:45:40 +01:00
commit ee8b7ef719
1 changed files with 114 additions and 107 deletions

View File

@ -408,6 +408,114 @@ if (isInputRange!R)
}
}
// Reverse-access-order range returned by `retro`.
private struct Retro(Range)
{
Range source;
@disable this();
private this(Range source)
{
this.source = source;
}
Retro save()
{
return this;
}
@property auto ref front()
in (!empty)
{
return this.source.back;
}
void popFront()
in (!empty)
{
this.source.popBack();
}
@property auto ref back()
in (!empty)
{
return this.source.front;
}
void popBack()
in (!empty)
{
this.source.popFront();
}
@property bool empty()
{
return this.source.empty;
}
static if (hasLength!Range)
{
@property size_t length()
{
return this.source.length;
}
}
static if (isRandomAccessRange!Range && hasLength!Range)
{
auto ref opIndex(size_t i)
in (i < length)
{
return this.source[$ - ++i];
}
}
static if (hasAssignableElements!Range)
{
@property void front(ref ElementType!Range value)
in (!empty)
{
this.source.back = value;
}
@property void front(ElementType!Range value)
in (!empty)
{
this.source.back = move(value);
}
@property void back(ref ElementType!Range value)
in (!empty)
{
this.source.front = value;
}
@property void back(ElementType!Range value)
in (!empty)
{
this.source.front = move(value);
}
static if (isRandomAccessRange!Range && hasLength!Range)
{
void opIndexAssign(ref ElementType!Range value, size_t i)
in (i < length)
{
this.source[$ - ++i] = value;
}
void opIndexAssign(ElementType!Range value, size_t i)
in (i < length)
{
this.source[$ - ++i] = move(value);
}
}
}
version (unittest) static assert(isBidirectionalRange!Retro);
}
/**
* Iterates a bidirectional range backwards.
*
@ -420,115 +528,14 @@ if (isInputRange!R)
*
* Returns: Bidirectional range with the elements order reversed.
*/
auto retro(Range)(Range range)
auto retro(Range)(return Range range)
if (isBidirectionalRange!Range)
{
static struct Retro
{
Range source;
@disable this();
private this(Range source)
{
this.source = source;
}
Retro save()
{
return this;
}
@property auto ref front()
in (!empty)
{
return this.source.back;
}
void popFront()
in (!empty)
{
this.source.popBack();
}
@property auto ref back()
in (!empty)
{
return this.source.front;
}
void popBack()
in (!empty)
{
this.source.popFront();
}
@property bool empty()
{
return this.source.empty;
}
static if (hasLength!Range)
{
@property size_t length()
{
return this.source.length;
}
}
static if (isRandomAccessRange!Range && hasLength!Range)
{
auto ref opIndex(size_t i)
in (i < length)
{
return this.source[$ - ++i];
}
}
static if (hasAssignableElements!Range)
{
@property void front(ref ElementType!Range value)
in (!empty)
{
this.source.back = value;
}
@property void front(ElementType!Range value)
in (!empty)
{
this.source.back = move(value);
}
@property void back(ref ElementType!Range value)
in (!empty)
{
this.source.front = value;
}
@property void back(ElementType!Range value)
in (!empty)
{
this.source.front = move(value);
}
static if (isRandomAccessRange!Range && hasLength!Range)
{
void opIndexAssign(ref ElementType!Range value, size_t i)
in (i < length)
{
this.source[$ - ++i] = value;
}
void opIndexAssign(ElementType!Range value, size_t i)
in (i < length)
{
this.source[$ - ++i] = move(value);
}
}
}
}
return Retro(range);
// Special case: retro(retro(range)) is range
static if (is(Range == Retro!RRange, RRange))
return range.source;
else
return Retro!Range(range);
}
///