Cannot use ostream support on fmt 9.x and 10.x

[ahoarau]

Hello ! I'm having compile issues on fmt 9.x and 10.x with the ostream extension. Same on msvc (latest) and gcc 13.2 : https://godbolt.org/z/8oejx8Yfn Thanks for the help !

#include <fmt/ostream.h>

struct A{};

std::ostream& operator<<(std::ostream& os, const A& a)
{
    os << "Hello !";
    return os;
}

int main()
{
    fmt::print("{}", A{});
}

7.x => ✅

8.x => ✅

9.x => ❌

10.x => ❌

[vitaut]

Duplicate of #3318.