llvm/llvm-project
[clang] [C++20] Defaulted `operator==` doesn't lookup in using-directive properly
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#97,087 opened on 2024/06/28
clang:frontendgood first issue
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説明
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