Class ContainsMatcher

tutorials/external/catch.hpp:3156–3159

            bool match( std::string const& source ) const override;
        };
        struct ContainsMatcher : StringMatcherBase {
            ContainsMatcher( CasedString const& comparator );
            bool match( std::string const& source ) const override;
        };
        struct StartsWithMatcher : StringMatcherBase {
            StartsWithMatcher( CasedString const& comparator );
            bool match( std::string const& source ) const override;