llvm/llvm-project

[clang] [C++20] Defaulted `operator==` doesn't lookup in using-directive properly

Open

#97 087 ouverte le 28 juin 2024

Voir sur GitHub
 (11 commentaires) (0 réactions) (0 assignés)C++ (10 782 forks)batch import
clang:frontendgood first issue

Métriques du dépôt

Stars
 (26 378 stars)
Métriques de merge PR
 (Merge moyen 1j 2h) (1 000 PRs mergées en 30 j)

Description

https://godbolt.org/z/c8v65nGzc

struct X {};
namespace NS {
    bool operator==(X, X);
}
using namespace NS;
struct Y {
    X x;
    friend bool operator==(Y, Y);
};
bool operator==(Y, Y) = default;
<source>:10:6: error: defaulting this equality comparison operator would delete it after its first declaration
   10 | bool operator==(Y, Y) = default;
      |      ^
<source>:7:7: note: defaulted 'operator==' is implicitly deleted because there is no viable 'operator==' for member 'x'
    7 |     X x;
      |       ^

If it is defaulted in the class it does compile and properly call NS::operator==(X, X): https://godbolt.org/z/M8Msc8T3a
If the function-body is replaced it also compiles: https://godbolt.org/z/19sEre7KW

Guide contributeur