int main()
{
std::cout << "4! = " ;
constN<factorial(4)> out1; // computed at compile time
volatile int k = 8;
std::cout << k << "! = " << factorial(k) << '\n'; // computed at run time
std::cout << "Number of lowercase letters in \"Hello, world!\" is ";
constN<countlower("Hello, world!")> out2; // implicitly converted to conststr
}
constexpr std::size_t countlower(conststr s, std::size_t n = 0,
std::size_t c = 0) {
return n == s.size() ? c :
s[n] >= 'a' && s[n] <= 'z' ? countlower(s, n+1, c+1) :
countlower(s, n+1, c);
}
int main()
{
std::cout << "Number of lowercase letters in \"Hello, world!\" is ";
constN<countlower("Hello, world!")>(); // implicitly converted to conststr
}