[clang] Discarding a use of a [[nodiscard]] `consteval` function does not emit a nodiscard warning

[smallp-o-p]

It emits an expression result unused warning instead. GCC emits the nodiscard warning.

[[nodiscard]] consteval int foo(){ return 1; }

[[nodiscard]] int foo2(){ return 1; }

int main(){
    foo(); // <-- emits an expression result unused warning
    foo2(); 
}

See: https://godbolt.org/z/9fEG8c5Mx

[frederick-vs-ja]

I don't think Clang is buggy for the original example. Clang is more aggressive on warning on discarding results of consteval functions, which is arguably a good thing.

But for this example, Clang ignores the user-provided message, which is somehow undesired. Godbolt link.

[[nodiscard("my message")]] consteval int foo(){ return 1; }

int main(){
    foo();
}