https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104041
Bug ID: 104041
Summary: static_assert failure triggered by non-selected
template specialization
Product: gcc
Version: 11.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: bugzilla at cems dot de
Target Milestone: ---
A static_assert failure can be triggered even by a template specialization that
is not selected.
The following code selects the specialization C<int> if allowed to compile, but
compilation fails if there is a failing static_assert in the generic template
C<T>, despite it not being selected.
#include <iostream>
template <typename T> struct C
{ C(T) {
#ifdef DEBUG
static_assert(false, "C<T> selected");
#endif
std::cout << "C<T> selected"; }
};
template <> struct C<int>
{ C(int) { std::cout << "C<int> selected"; }
};
int main()
{ C c(1);
}
/*
with macro DEBUG defined, compilation error with diagnostic:
error: static assertion failed: C<T> selected
without macro DEBUG defined, compiles and runs with output:
C<int> selected
*/
