Calculating and printing factorial at compile time in C++

Question

template
struct Factorial {
    enum { value = n * Factorial::value};
};

template<>
struct Factorial<0> {
    enum {val         


        

Answer 1

I am sure it is far too late, but still.

// definition
template
struct print_constexpr{
    [[deprecated]]
    print_constexpr(){ }
};

// usage
print_constexpr::value> x;

// output
{path to file}: warning: ‘print_constexpr::print_constexpr() [with T = unsigned int; T N = 120]’ is deprecated [-Wdeprecated-declarations]
    print_constexpr::value> x;