Method BasicResult

tutorials/external/catch.hpp:7107–7112

    public:
        template<typename U>
        explicit BasicResult( BasicResult<U> const &other )
        :   ResultValueBase<T>( other.type() ),
            m_errorMessage( other.errorMessage() )
        {
            assert( type() != ResultBase::Ok );
        }

        template<typename U>
        static auto ok( U const &value ) -> BasicResult { return { ResultBase::Ok, value }; }