#include <filesystem>
#include <iostream>
namespace fs = std::filesystem;
int main()
try
{
    auto ret1 = fs::file_size("../main.cpp");
    std::cout << "size = " << ret1 << '\n';
    auto ret2 = fs::file_size("../жопа.txt");
    std::cout << "size = " << ret2 << '\n';
}
catch(fs::filesystem_error& e)
{
    std::cout << e.what() << '\n';
}
a.exe
size = 362
file_size: The system cannot find the file specified.: "../╨╢╨╛╨┐╨░.txt"

#include <filesystem>
#include <iostream>
namespace fs = std::filesystem;
int main()
try
{
    auto ret1 = fs::file_size("../main.cpp");
    std::cout << "size = " << ret1 << '\n';
    auto ret2 = fs::file_size("../жопа.txt");
    std::cout << "size = " << ret2 << '\n';
}
catch(fs::filesystem_error& e)
{
    std::cout << e.what() << '\n';
}
a.exe
size = 362
file_size: The system cannot find the file specified.: "../╨╢╨╛╨┐╨░.txt"

#include <filesystem>
#include <iostream>
namespace fs = std::filesystem;
int main()
try
{
    auto ret1 = fs::file_size("../main.cpp");
    std::cout << "size = " << ret1 << '\n';
    auto ret2 = fs::file_size("../жопа.txt");
    std::cout << "size = " << ret2 << '\n';
}
catch(fs::filesystem_error& e)
{
    std::cout << e.what() << '\n';
}
a.exe
size = 362
file_size: The system cannot find the file specified.: "../╨╢╨╛╨┐╨░.txt"