To further improve our outputs, e.g., structuring with different levels, using a Logger library might be an improvement. I suggest replacing the `debout` Macro with calls to `spdlog` (https://github.com/gabime/spdlog) which is a header only library. It also allows easier formatting with `fmt` (https://github.com/fmtlib/fmt, will become part of the standard in C++20). ```cpp #include <spdlog/spdlog.h> void foo(){ SPDLOG_WARN("Warning"); } int main(int, char**) { spdlog::set_pattern("%! in %s line %#: %v"); // For printing info which file and function. spdlog::set_level(spdlog::level::info); int a = 2; SPDLOG_INFO("This is a test: a = {:04d}", a); SPDLOG_ERROR("Error message"); SPDLOG_DEBUG("This is not getting printed as level is at info"); foo(); } ``` output: ``` main in main.cpp line 12: This is a test: a = 0002 main in main.cpp line 13: Error message foo in main.cpp line 4: Warning ```