https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111831
Bug ID: 111831
Summary: friend with requires keyword compilation error
Product: gcc
Version: 13.2.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: janezz55 at gmail dot com
Target Milestone: ---
If I compile list.cpp with:
g++ -std=c++20 list.cpp -o l
friend auto operator==(list const& l, list const& r)
noexcept(noexcept(
std::equal(l.begin(), l.end(), r.begin(), r.end())
)
)
requires(requires{std::equal(l.begin(), l.end(), r.begin(), r.end());})
{
return std::equal(l.begin(), l.end(), r.begin(), r.end());
}
gcc-13.2.1 will respond with a compilation error:
error: no match for 'operator==' (operand types are 'xl::list<int>' and
'xl::list<int>')
51 | std::cout << a.size() << " " << b.size() << " " << (a == b) <<
std::endl;
| ~ ^~ ~
| | |
| | list<[...]>
| list<[...]>
bug clang-16.0.6 won't. I think the bug is related to the friend declaration. I
have prepared an example:
https://github.com/user1095108/xl/blob/master/list.cpp
The relevant requires inside list.hpp is commented out, since the requires
serves no purpose at all in this case. Please uncomment, if you decide to
investigate.
