POSIX Program Argument Syntax Conventions

[Limag]

It would be very nice if this library could support the POSIX syntax convention, including the GNU extension that the long option uses an equal sign:
To specify an argument for a long option, write ‘--name=value’

More details e.g. here:
https://www.gnu.org/software/libc/manual/html_node/Argument-Syntax.html