Return true if this command-line object's option having the specified name has a defined value, and false otherwise. An option has a defined value if isSpecified(name) or if a default value was configured for the option (see {Occurrence Information Field}). The behavior is undefined unless this command-line object isParsed() and hasOption(name).
Declared in <balcl_commandline.h>
bool
hasValue(std::string_view const& name) const;