Ternary Operator / `select`

[ax3l]

Hi,

Can we as a preview to C++26 implement already vir::stdx::select (for std::simd::select)?

This is a very common pattern in vectorized code that contains the (scalar) ternary operator, e.g.

• SIMD: Add where and ternary operator AMReX-Codes/amrex#5095
• https://kokkos.org/kokkos-core-wiki/ProgrammingGuide/SIMD.html#ternary-operator

[mattkretz]

🙉 and again I didn't see the issue. Sorry.

Yes adding a select function would be fairly simple and useful for writing forward-looking code.
Since it can't be part of libstdc++ it would simply exist unconditionally in vir-simd.

[mattkretz]

Also: https://github.com/mattkretz/gcc/tree/P0917_overloadable_conditional_operator makes operator?: overloadable. You can use https://github.com/mattkretz/cplusplus-ci/pkgs/container/cplusplus-ci%2Fgccp0917 to play with it. We might just want to implement it as operator?: in addition to select.

[ax3l]

Ah, overloading operator?: would be lovely on the long run!

Yes, simply adding unconditionally in vir-simd for now as a helper function would be splendid.