boolalpha capitalize

Question

How do you capitalize the output generated by the cout of boolean values.

I know that if I did:

cout << boolalpha << true;

it will output

true

how do I get it to output

True

I have some feeling it has to do with do_truename and do_falsename, but I have no clue how to do it.

Answer 1

For a fleeting moment I thought that this could be done using std::uppercase but this doesn't seem to be the case: these only apply to things like the hexadecimal digits and the exponent. So, it seems it, indeed, requires a std::numpunct<char> override which is, however, not that bad:

#include <iostream>
#include <locale>

struct numpunct
    : std::numpunct<char>
{
    std::string do_truename() const { return "True"; }
    std::string do_falsename() const { return "False"; }
};

int main()
{
    std::locale loc(std::cout.getloc(), new numpunct);
    std::cout.imbue(loc);
    std::cout << std::boolalpha << true << "\n";
}