https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87399
Bug ID: 87399
Summary: Inconsistent determination of what is usable in a
constant expression with __PRETTY_FUNCTION__
Product: gcc
Version: 9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: barry.revzin at gmail dot com
Target Milestone: ---
Reduced from StackOverflow (https://stackoverflow.com/q/52472000/2069064):
template <int>
struct X { };
constexpr int f(char const *s)
{
return *s;
}
void test()
{
constexpr int i = f(__PRETTY_FUNCTION__);
X<i> x;
X<f(__PRETTY_FUNCTION__)> y;
}
gcc accepts the declaration of x and rejects the declaration of y. clang
accepts both. I am not sure, but based on my reading of [expr.const], since
__PRETTY_FUNCTION__ is not defined with constexpr, we run afoul of 2.7, and
both declarations of x and y should be rejected?
Either way, it seems like either both should be accepted or both should be
rejected.
