On 11/13/19 2:42 PM, Andrew Sutton wrote:
Suppress diagnostics when substituting into requires-expressions outside of concept definitions.This change broke one existing test, which I've updated to match the behavior of the current patch. Specifically, it changed the case below: template<typename T> constexpr bool subst = true; template<typename U> constexpr bool test() { if constexpr (requires { requires subst<U&>; }) // error? return true; else return false; } static_assert(!test<void>()); Before, the program is ill-formed as a result of substituting void for U. After applying, the requirement is false. If you replace the requires-expression with a concept (either before or after the patch), you get false. So, this seems like the right behavior.
OK. Jason
