Logger vlk https://godbolt.org/g/KSSx5f

log.hpp

#include <iostream>
#include <array>

enum Log_level
{
    L_SILENT = 0,
    L_ERROR = 1,
    L_INFO = 2,
    L_DEBUG = 3,
};

static Log_level log_level = L_ERROR;

static constexpr std::array<const char*, 4> log_colors 
{
    "",
    "\x1B[1;31m",
    "\x1B[1;34m",
    "\x1B[1;30m"
};

template<typename... Args>
void vlk_log_internal(const Log_level level, const char* msg, Args&&... args)
{
    if (level > log_level)
    {
        return;
    }
    std::FILE* output = (level == L_ERROR ? stderr : stdout);

    std::fprintf(output, "%s", log_colors[level]);
    std::fprintf(output, msg, std::forward<Args>(args)...);
    std::fprintf(output, "\x1B[0m");
    std::fprintf(output, "\n");

}

#define vlk_log(lvl, msg, ...) { vlk_log_internal(lvl, "[%s:%d] " msg, __FILE__, __LINE__, ##__VA_ARGS__); } (void)0

int main()
{
    log_level = L_SILENT;

    vlk_log(L_ERROR, "Error will not show");

    log_level = L_ERROR;

    vlk_log(L_ERROR, "Error %s", "msg");
    vlk_log(L_INFO, "Info will not show");

    log_level = L_INFO;

    vlk_log(L_INFO, "Info %s", "msg");
    vlk_log(L_DEBUG, "Debug will not show");

    log_level = L_DEBUG;

    vlk_log(L_DEBUG, "Debug %s", "msg");

    return 0;   
}