spdlog
Fast C++ logging library
...For example, if you only need rotating logger, you need to include "spdlog/sinks/rotating_file_sink.h". spdlog provides various log targets, which are, rotating log files, daily log files, console logging (colors supported), syslog, Windows event log, and Windows debugger (OutputDebugString(..)). Easily extendable with custom log targets. Log filtering, log levels can be modified in runtime as well as in compile time. Support for loading log levels from argv or from environment var. Backtrace support, store debug messages in a ring buffer and display later on demand.