[libcxx-commits] [PATCH] D144363: [libcxx] <experimental/simd> Added simd width functions, simd_size traits and related tests

[Yin Zhang via Phabricator via libcxx-commits]

Joy12138 added a comment.

In D144363#4491370 <https://reviews.llvm.org/D144363#4491370>, @philnik wrote:

> I think you did something wrong. You shouldn't need a `.verify.cpp` for SFINAE testing, and looking at the error message the types don't SFINAE away.
>
> Something like
>
>   template <class T, class U, class = void>
>   struct check_sfinae : false_type {};
>   
>   template <class T, class U>
>   struct check_sfinae<void_t<ex::simd_size<T, U>>> : true_type {};
>   
>   static_assert(!check_sfinae<int , ex::native_simd<int>>::value);
>
> should work just fine in a normal `.pass.cpp`. If you get an error, either I did something wrong in the SFINAE test, or the implementation of `ex::simd_size` is wrong (because it doesn't SFINAE away).
>
> I'm pretty sure that variable templates can't SFINAE away.

@philnik Hi, we rewrite the SFINAE test as you given style. It seems no errors come out. Does it mean our implementations right?


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