ezOptionParser

It's another command-line parser class for C++ that has features not available in alternative solutions (getopt, boost, argtable, argstream, gflags) and doesn't require a steep learning curve. It uses only a single header file, allows arbitrary option flag names, arbitrary argument list delimiters, flag and flagless argument grouping, expected argument list length validation and conversion, validation of options by datatype ranges or user range or sets, saving and loading options file with comments embedded.