This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 116a. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.
2024-12-19
Given an example like
template <class T> void f (T, int = T()); template <class T> auto g(T t) -> decltype (f(t)); void g(int); struct A { A(int); operator int(); }; int main() { g(A(42)); }
it seems that since the default argument is treated as a separate template, its ill-formedness causes a hard error, rather than a substitution failure for g. Is this what we want?
Rationale (October, 2012):
CWG felt that this was acceptable; also, there is discussion in EWG regarding changes to the SFINAE rules that could affect this case.