https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86818
Bug ID: 86818
Summary: injected-class-name interpreted as type instead of
constructor
Product: gcc
Version: 7.3.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: barry.revzin at gmail dot com
Target Milestone: ---
From https://stackoverflow.com/q/51621560/2069064:
template <class> using void_t = void;
template <class C, class = void>
struct X {
static constexpr bool value = false;
};
template <class C>
struct X<C, void_t<typename C::T> > {
static constexpr bool value = true;
};
struct T { };
static_assert(!X<T>::value);
According to [class.qual], I think "typename C::T" should be considered to name
the constructor of C when C is T, so the assert should NOT trigger (because
typename C::T is not a type, so we fallback to the primary template). This
program compiles on clang, fails on gcc.
