Code Timing Macro (C++)

time_code.h

// You must have #included <chrono> and <cstdio>

#define TIME_CODE(code, name) do                                                       \
{                                                                                      \
    using namespace std::chrono;                                                                 \
    const auto i(system_clock::now());                                                 \
    { code }                                                                           \
    const auto j(system_clock::now());                                                 \
    std::fprintf(stderr, "Task %s took %lfs\n", name, duration<double>(j - i).count());\
} while(0)