[Bug c++/106313] New: GCC incorrectly compiles code involving concept

[Bug c++/106313] New: GCC incorrectly compiles code involving concept

[jlame646 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106313

            Bug ID: 106313
           Summary: GCC incorrectly compiles code involving concept
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jlame646 at gmail dot com
  Target Milestone: ---

The following program is compiled in gcc 12.1 even though it should not as
`obj` is not a constant expression. A working demo can be seen
here:https://godbolt.org/z/aqoMGazfd

```
template<bool op>
class Person
{
    const bool own_pet;

public:
    Person() : own_pet(op) {}
    consteval bool OwnPet() const { return own_pet; }
    consteval bool OwnPetC() const { return true; }
    void PatPet() const {}
};

template<typename T>
concept MustOwnPet = requires(T obj) {
    requires obj.OwnPet();
};

void pat(const MustOwnPet auto& p)
{
    p.PatPet();
}

template<typename T>
concept MustOwnPetC = requires(T obj) {
    requires obj.OwnPetC();
};

void pat_c(const MustOwnPetC auto& p)
{
    p.PatPet();
}

int main()
{

    pat_c(Person<true>()); 

    return 0;
}
```

[Bug c++/106313] GCC incorrectly compiles code involving concept

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106313

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2022-07-15
             Status|UNCONFIRMED                 |NEW
           Keywords|                            |accepts-invalid
     Ever confirmed|0                           |1

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
MSVC accepts this too, although EDG points out that 'obj' is not a constant,
and Clang points out that it cannot be evaluated.