https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119056
Bug ID: 119056
Summary: class template with non-type argument does not
recognize copy/move constructor prototype when
parameter is not using the template argument
Product: gcc
Version: 14.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: sandberg.sven at gmail dot com
Target Milestone: ---
This does not compile with any gcc version up to 14.2.0 or trunk
(https://godbolt.org/z/61av75zzx):
```
#include <concepts> // same_as
template <bool x>
class C {
static constexpr bool m_x = x;
public:
static_assert(std::same_as<C<x>, C<m_x>>); // ok
C(const C<x> &) = default; // ok
C(C<m_x> &&) = default; // error: 'C<x>::C(C<m_x>&&)' cannot be
defaulted
};
```
It does compile on clang. The same issue occurs for all copy/move constructors
and copy/move assignment operators.
Apparently, gcc does not recognize that the prototype is a copy constructor
(copy/move constructor/operator) when the parameter type's template argument is
specified using the static constexpr member variable `m_x` instead of the
template argument `x`.
