Method c_str

extlibs/catch/include/catch/catch.hpp:13281–13287

    }

    auto StringRef::c_str() const -> char const* {
        if( !isSubstring() )
            return m_start;

        const_cast<StringRef *>( this )->takeOwnership();
        return m_data;
    }
    auto StringRef::currentData() const noexcept -> char const* {
        return m_start;
    }