[Bug c++/103700] Incomplete type not causing constraints to fail

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103700

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Here is a C++14 testcase too:

template<class T>
    auto f(T a) -> decltype(a+1) { return a+1; }
template<class T>
    auto f(T a) {return a;}
struct Incomplete *p;
auto b = f(p);