std::chrono::treat_as_floating_point

Since C++11

Header: <chrono>

The std::chrono::treat_as_floating_point trait helps determine if a duration can be converted to another duration with a different tick period.

# Declarations

template< class Rep >
struct treat_as_floating_point : std::is_floating_point<Rep> {};

(since C++11)

# Example

#include <chrono>
#include <iostream>
#include <thread>
 
void timed_piece_of_code() 
{
    std::chrono::milliseconds simulated_work(2);
    std::this_thread::sleep_for(simulated_work);
}
 
int main() 
{
    auto start = std::chrono::high_resolution_clock::now();
 
    std::cout << "Running some timed piece of code...\n";
    timed_piece_of_code();
 
    auto stop = std::chrono::high_resolution_clock::now();
 
    // A floating point milliseconds type
    using FpMilliseconds = 
        std::chrono::duration<float, std::chrono::milliseconds::period>;
 
    static_assert(std::chrono::treat_as_floating_point<FpMilliseconds::rep>::value, 
                  "Rep required to be floating point");
 
    // Note that implicit conversion is not allowed here    
    auto i_ms = std::chrono::duration_cast<std::chrono::milliseconds>(stop - start);
 
    // Note that implicit conversion is allowed here
    auto f_ms = FpMilliseconds(stop - start);
 
    std::cout << "Timing stats:\n";
 
    std::cout << "  Time in milliseconds, using default rep: "
              << i_ms.count() << '\n';
 
    std::cout << "  Time in milliseconds, using floating point rep: "
              << f_ms.count() << '\n';
}