[libcxx-commits] [clang] [libcxx] [Clang] Implement CWG2369 "Ordering between constraints and substitution" (PR #102857)

[Younan Zhang via libcxx-commits]

zyn0217 wrote:

> Is kinda wrong, it should be in the instantiation of that function...

@erichkeane I don’t quite understand: the CWG issue itself requires us to check the constraint before substituting into the function during template argument deduction. So it shouldn’t live in a specialization because we don’t really have one. This situation feels more like a chicken-and-egg problem.

GCC doesn’t encounter this issue because it doesn’t need to support the MSVC ABI. The problem only arises with the MSVC ABI because it requires parent mangling when instantiating the lambda body.

https://github.com/llvm/llvm-project/pull/102857