cxxopts is a lightweight C++ command line option parser library that supports standard GNU-style syntax for options.
The tool solves the problem of parsing command line arguments in C++ programs. It handles long options, short options, combined short options, and positional arguments following the `--` separator. The parser accepts options in forms like `--long`, `--long=argument`, `-a`, or `-abc argument`, and allows any type that supports the `>>` operator to be used as an option value.
Developers should choose this tool for straightforward command line parsing in C++ applications where a lightweight dependency is preferred over heavier frameworks. It suits projects that need GNU-style option syntax without extensive configuration overhead. The library provides help message generation with support for grouping options, exception-based error handling with distinct exception types for specification and parsing errors, and the ability to skip unrecognized arguments. Version 3 introduced a breaking change where the parser no longer modifies its input arguments, allowing const argc and argv to be passed safely, and the ParseResult object can now be returned from outside the parser's scope.
The project maintains a clear separation between master branch development work and stable tagged release versions. The codebase demonstrates active refinement of its core parsing logic, with deliberate design decisions around immutability of input and lifetime management of parse results. Development shows attention to exception hierarchy design and the ability to extend the parser with custom types through operator overloading.
