https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106734
Bug ID: 106734
Summary: [requires] std::same_as in compound requirements
doesn't produce expected result
Product: gcc
Version: 12.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: jakob at schmutz dot co.uk
Target Milestone: ---
On gcc version 12.2.0 (and 11.3.0) I would expect the following code
```
#include <iostream>
struct Bar {
};
int main()
{
Bar bar;
constexpr bool same = requires
{
{ bar } -> std::same_as<Bar>;
};
constexpr bool conv = requires
{
{ bar } -> std::convertible_to<Bar>;
};
if constexpr (std::same_as<decltype(bar), Bar>)
{
std::cout << "AS SAME" << std::endl;
}
if constexpr (std::is_same_v<decltype(bar), Bar>)
{
std::cout << "IS SAME" << std::endl;
}
if constexpr (same)
{
std::cout << "REQUIRES SAME" << std::endl;
}
if constexpr (conv)
{
std::cout << "CONVERTIBLE" << std::endl;
}
return 0;
}
```
to return
```
AS SAME
IS SAME
REQUIRES SAME
CONVERTIBLE
```
based on how how [compound
requires](https://en.cppreference.com/w/cpp/language/requires) section reads
but instead it returns
```
IS SAME
REQUIRES SAME
CONVERTIBLE
```
compiled with `g++ temp.cpp -std=c++20`
compiling with `clang++ temp.cpp -std=c++20` produces the expected output
