Method MatchExpr

tutorials/external/catch.hpp:3373–3378

        StringRef m_matcherString;
    public:
        MatchExpr( ArgT const& arg, MatcherT const& matcher, StringRef const& matcherString )
        :   ITransientExpression{ true, matcher.match( arg ) },
            m_arg( arg ),
            m_matcher( matcher ),
            m_matcherString( matcherString )
        {}

        void streamReconstructedExpression( std::ostream &os ) const override {
            auto matcherAsString = m_matcher.toString();