Method set

tests/catch.h:4060–4062

        struct BoundDataMember : IArgFunction<C>{
            BoundDataMember( M C::* _member ) : member( _member ) {}
            virtual void set( C& p, std::string const& stringValue ) const {
                convertInto( stringValue, p.*member );
            }
            virtual void setFlag( C& p ) const {
                convertInto( true, p.*member );
            }