[libc++] Fix `unexpected` heterogeneous comparison (#115249)
Currently, libc++ incorrectly rejects heterogeneous comparison of
`unexpected`, because the `operator==` is only a hidden friend of
`unexpected<_Err>` but not of `unexpected<_Err2>`. We need to call the
`error()` member function on `__y`.
Fixes #115326
diff --git a/libcxx/include/__expected/unexpected.h b/libcxx/include/__expected/unexpected.h
index c7fe3c5..cf110bc 100644
--- a/libcxx/include/__expected/unexpected.h
+++ b/libcxx/include/__expected/unexpected.h
@@ -108,7 +108,7 @@
template <class _Err2>
_LIBCPP_HIDE_FROM_ABI friend constexpr bool operator==(const unexpected& __x, const unexpected<_Err2>& __y) {
- return __x.__unex_ == __y.__unex_;
+ return __x.__unex_ == __y.error();
}
private:
diff --git a/libcxx/test/std/utilities/expected/expected.unexpected/equality.pass.cpp b/libcxx/test/std/utilities/expected/expected.unexpected/equality.pass.cpp
index 3c29cf9..4824151 100644
--- a/libcxx/test/std/utilities/expected/expected.unexpected/equality.pass.cpp
+++ b/libcxx/test/std/utilities/expected/expected.unexpected/equality.pass.cpp
@@ -20,18 +20,29 @@
#include <expected>
#include <utility>
-struct Error{
+struct Error {
int i;
friend constexpr bool operator==(const Error&, const Error&) = default;
+ friend constexpr bool operator==(const Error& lhs, int rhs) noexcept { return lhs.i == rhs; }
};
constexpr bool test() {
std::unexpected<Error> unex1(Error{2});
std::unexpected<Error> unex2(Error{3});
std::unexpected<Error> unex3(Error{2});
+
assert(unex1 == unex3);
assert(unex1 != unex2);
assert(unex2 != unex3);
+
+ std::unexpected<int> unex_i1(1);
+ std::unexpected<int> unex_i2(2);
+
+ assert(unex1 != unex_i1);
+ assert(unex_i1 != unex1);
+ assert(unex1 == unex_i2);
+ assert(unex_i2 == unex1);
+
return true;
}
