https://github.com/HerrCai0907 commented:
That is not true, when then overloaded operation provide the partial order
sema, when the check will cause the wrong result.
e.g.
```c++
#include <compare>
#include <iostream>
struct A {
int v;
bool isValid;
std::partial_ordering operator<=>(const A &other) const {
if (!isValid || !other.isValid) {
return std::partial_ordering::unordered;
}
if (v < other.v) {
return std::partial_ordering::less;
} else if (v > other.v) {
return std::partial_ordering::greater;
} else {
return std::partial_ordering::equivalent;
}
}
};
int main() {
A a{5, true};
A b{0, false};
std::cout << "a > b: " << (a > b) << std::endl;
std::cout << "a <= b: " << (a <= b) << std::endl;
return 0;
}
```
The result will be
```
a > b: 0
a <= b: 0
```
https://github.com/llvm/llvm-project/pull/164141
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