system clock's time_point: min and max, C++ (vc++)

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#include <chrono>
#include <ctime>
#include <string>
#include <iostream>

std::string as_string( const std::chrono::system_clock::time_point& tp )
{
    const std::time_t t = std::chrono::system_clock::to_time_t(tp);

const auto ptm = std::localtime( std::addressof(t) ) ;
    if(ptm) // if the c library supports this value for time_t
    {
        char buffer[1024] {} ;
        if( std::strftime( buffer, sizeof(buffer), "%A, %B %d %H:%M:%S %Y", ptm ) )
            return buffer ;
    }

// this time point is outside the range of what the C library can handle gracefully
    using years = std::chrono::duration< long long, std::ratio<(3*365+366)*24LL*60*60/4> > ;
    const auto nyears = std::chrono::duration_cast<years>( tp.time_since_epoch() ).count() ;
    return nyears < 0 ? "about " + std::to_string(-nyears) + " years before epoch" :
                        "about " + std::to_string(nyears) + " years after epoch" ;
}

int main()
{
    using time_point_t = std::chrono::system_clock::time_point ;

// print the epoch of this system clock:
    std::cout << "epoch: " << as_string( time_point_t{} ) << '\n';

// print current time:
    std::cout << "now:   " << as_string( std::chrono::system_clock::now() ) << '\n';

// print minimum time of this system clock:
    std::cout << "min:   " << as_string( time_point_t::min() ) << '\n';

// print maximum time of this system clock:
    std::cout << "max:   " << as_string( time_point_t::max() ) << '\n';
}

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Compilation time: 7,69 sec, absolute running time: 0,33 sec, absolute service time: 8,03 sec