https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114580
Bug ID: 114580
Summary: Bogus warning on if constexpr
Product: gcc
Version: 14.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: jakub at gcc dot gnu.org
Target Milestone: ---
#include <type_traits>
template <typename T>
void foo ()
{
if constexpr ((T) std::is_constant_evaluated ())
;
}
void
bar ()
{
foo <bool> ();
}
emits bogus warning with -std=c++17 -Wall.
Once it (incorrectly) warns about
warning: ‘std::is_constant_evaluated’ always evaluates to false in a
non-‘constexpr’ function [-Wtautological-compare]
and once it correctly warns about
warning: ‘std::is_constant_evaluated’ always evaluates to true in ‘if
constexpr’ [-Wtautological-compare]
on the same line. In reality, std::is_constant_evaluated () here always
evaluates to true, never to false.
