Add an optimization for:
Range2 copy(Range1, Range2)(Range1 source, Range2 target);
...to use the c function memmove when it is safe to do so and the two ranges overlap each other (when they don't overlap, a vectorized copy should be faster). As far as I can tell, it is safe to use memmove for copying source over target if all of the following are true:
1) Both ranges are arrays (static or dynamic)
2) Both arrays have the same element type
3) hasElaborateAssign!T is false for the element type T
I haven't benchmarked anything, but all the good C++ standard library implementations of std::copy seem to do this optimization, and I trust that they know what they are doing.
Comment #1 by tommitissari — 2013-06-18T06:03:11Z
(In reply to comment #0)
> Add an optimization for:
>
> Range2 copy(Range1, Range2)(Range1 source, Range2 target);
>
> ...to use the c function memmove when it is safe to do so and the two ranges
> overlap each other (when they don't overlap, a vectorized copy should be
> faster). As far as I can tell, it is safe to use memmove for copying source
> over target if all of the following are true:
>
> 1) Both ranges are arrays (static or dynamic)
> 2) Both arrays have the same element type
> 3) hasElaborateAssign!T is false for the element type T
>
> I haven't benchmarked anything, but all the good C++ standard library
> implementations of std::copy seem to do this optimization, and I trust that
> they know what they are doing.
Also, the documentation for std.algorithm.copy should be changed to indicate that the ranges are allowed to overlap if the above conditions hold.
Comment #2 by robert.schadek — 2024-12-01T16:17:58Z