# std::filesystem::file_time_type

From cppreference.com
< cpp‎ | filesystem

Defined in header `<filesystem>` |  |
using file_time_type = std::chrono::time_point </*trivial-clock*/>; |  | (since C++17) (until C++20)
using file_time_type = std::chrono::time_point < std::chrono::file_clock >; |  | (since C++20)

Represents file time.

`trivial-clock` is an implementation-defined type that satisfies TrivialClock and is sufficient to represent the resolution and range of the file time values offered by the filesystem. | (until C++20)

### Example

Run this code

    #include <iostream>
    #include <chrono>
    #include <iomanip>
    #include <fstream>
    #include <filesystem>
    namespace fs = std::filesystem;
    using namespace std::chrono_literals;
    int main()
    {
        fs::path p = fs::current_path() / "example.bin";
        std::ofstream(p.c_str()).put('a'); // create file
        auto ftime = fs::last_write_time(p);

        // assuming system_clock for this demo
        // note: not true on MSVC or GCC 9; C++20 will allow portable output
        std::time_t cftime = decltype(ftime)::clock::to_time_t(ftime);
        std::cout << "File write time is " << std::asctime(std::localtime(&cftime)) << '\n';

        fs::last_write_time(p, ftime + 1h); // move file write time 1 hour to the future
        ftime = fs::last_write_time(p); // read back from the filesystem

        cftime = decltype(ftime)::clock::to_time_t(ftime);
        std::cout << "File write time is " << std::asctime(std::localtime(&cftime)) << '\n';
        fs::remove(p);
    }

Possible output:

    File write time is Tue Mar 31 19:47:04 2015

    File write time is Tue Mar 31 20:47:04 2015

### See also

last_write_time (C++17) | gets or sets the time of the last data modification (function)

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