https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106212
Bug ID: 106212
Summary: Code becomes non-constexpr with _GLIBCXX_DEBUG
Product: gcc
Version: 13.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: fiesh at zefix dot tv
Target Milestone: ---
Consider the following C++20 code:
#include <array>
struct P {
constexpr P(int i) : e{i} {}
auto operator<=>(P const &) const = default;
std::array<int, 1> e;
};
constexpr auto operator-(P lhs, P) { return lhs; }
constexpr P p{1}, q{0};
static_assert(p - q != 0);
It behaves as follows:
* g++ compiles it successfully
* g++ with -D_GLIBCXX_DEBUG does not compile it
* clang++ compiles it successfully
* clang++ -D_GLIBCXX_DEBUG compiles it successfully
See also https://godbolt.org/z/ve19v1re9
