https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115251
Bug ID: 115251
Summary: [DR 1581] Conversion operator that is needed for
constant evaluation not instantiated in
requires-expression
Product: gcc
Version: 15.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: mital at mitalashok dot co.uk
Target Milestone: ---
Discovered at https://github.com/llvm/llvm-project/issues/93364
struct Universal {
template <typename T>
constexpr operator T() {
static_assert(false);
}
};
static_assert(requires { int{Universal()}; });
template<typename T>
struct NotUniversal {
constexpr operator T() {
static_assert(false);
}
};
static_assert(requires { int{NotUniversal<int>()}; });
These are both accepted even though it should instantiate the operator.
Changing the assert to use `sizeof` instead of `requires` causes this to not
compile as expected.
https://godbolt.org/z/En3PjaYzc
