set_metavar()
Rationale
This method allows you to specify a custom metavar. A metavar is the string it is printed next to the argument name when invoking the --help
builtin that helps you understand where you have to specify the value of the argument.
Example: program_name --out output_file
In the example above output_file is the metavar.
Example usage
parser.add_argument("--out", "-O").set_metavar("output_file");
Source Code
Arg &set_metavar(const std::string &metavar)
{
this->metavar = metavar;
return *this;
}