Support for C++ standard algorithms #4315
Conversation
|
|
||
| // swap | ||
| template <class T> | ||
| KOKKOS_INLINE_FUNCTION void swap(T& a, T& b) noexcept { |
There was a problem hiding this comment.
Note: this noexcept specification differs from the one in the standard. At a minimum we should document that.
C++20 changes how swap is found. Users are no longer required to specialized std::swap; rather, they just have to put a non-member function in the same namespace as their type. Should we support that kind of lookup here?
There was a problem hiding this comment.
I added that to be consistent with std syntax - i have to read more about this.
There was a problem hiding this comment.
Because we need operations that cannot fail as building blocks, noexcept really matters for the following operations (as far as optimizations made in the standard library):
Move construction
Move assignment
Swap
For swap, noexcept is conditional based on the noexcept-ness of the underlying move operations until C++17, then uses the is_nothrow_swappable trait (with the change in how swap is called as I described in the note above).
Also, there is a subtle difference between noexcept and not throwing. noexcept has semantics: an exception will not escape a function marked noexcept; rather, if one is about to escape, std::terminate is called. In the above, I'm specifically talking about functions marked noexcept.
There was a problem hiding this comment.
I am always unsure on this stuff. but we may just want to remove this. In particular the requirement for std::terminate if one tries to escape is kinda shitty, since it actually requires inserting a try/catch by the compiler or?
cz4rs
changed the title
There was a problem hiding this comment.
Apart from critically examining #4315 (comment), SortingOperations, MinMaxElementOperations and PartitioningOperations look good to me.
algorithms/src/std_algorithms/Kokkos_MinMaxElementOperations.hpp
Outdated
Show resolved
Hide resolved
algorithms/src/std_algorithms/Kokkos_PartitioningOperations.hpp
Outdated
Show resolved
Hide resolved
- fix comparison between signed and unsigned integers in tests - fix return type in std::count implementation
crtrott
dismissed
nliber’s stale review
checked the comments and it looks like its addressed
Add support for C++ standard algorithms
This adds support for C++ standard algorithms from categories A and B.
Note: replaces PR #4108.
Fixes #4075
Fixes #4076