operator bool

[bumbar1]

Not sure if it's a bug (maybe it's expected behavior because of bool?), but if you define a custom data type with operator bool (regardless of return value) and operator <<, then formatting doesn't work.

Example code:

#include <iostream>
#include <string>
#include "cppformat/format.h"

struct Date {
    operator bool() const { return true; }
    friend
    std::ostream& operator << (std::ostream& os, const Date& date) { return os << "1.1.1970"; }
};

int main() {
    std::cout << "date is " << Date{} << "\n";
    std::cout << fmt::format("date is {}\n", Date{}); // prints "date is 1"
}

[vitaut]

I think this has been fixed already in 6cff6d8. The commit message mentions enums but the same applies for any type implicitly convertible to int. Using the current master branch I get:

date is 1.1.1970
date is 1.1.1970

[bumbar1]

Ah yes, apologies. I wasn't using the latest version. It's working with operator bool defined. Thanks.

[vitaut]

No problems. Thanks for the confirmation.