Class StringRef

tutorials/external/catch.hpp:520–609

A non-owning string class (similar to the forthcoming std::string_view) Note that, because a StringRef may be a substring of another string, it may not be null terminated. c_str() must return a null terminated string, however, and so the StringRef will internally take ownership (taking a copy), if necessary. In theory this ownership is not externally visible - but it does mean (substring) StringRe

    /// visible - but it does mean (substring) StringRefs should not be shared between
    /// threads.
    class StringRef {
    public:
        using size_type = std::size_t;

    private:
        friend struct StringRefTestAccess;

        char const* m_start;
        size_type m_size;

        char* m_data = nullptr;

        void takeOwnership();

        static constexpr char const* const s_empty = "";

    public: // construction/ assignment
        StringRef() noexcept
        :   StringRef( s_empty, 0 )
        {}

        StringRef( StringRef const& other ) noexcept
        :   m_start( other.m_start ),
            m_size( other.m_size )
        {}

        StringRef( StringRef&& other ) noexcept
        :   m_start( other.m_start ),
            m_size( other.m_size ),
            m_data( other.m_data )
        {
            other.m_data = nullptr;
        }

        StringRef( char const* rawChars ) noexcept;

        StringRef( char const* rawChars, size_type size ) noexcept
        :   m_start( rawChars ),
            m_size( size )
        {}

        StringRef( std::string const& stdString ) noexcept
        :   m_start( stdString.c_str() ),
            m_size( stdString.size() )
        {}

        ~StringRef() noexcept {
            delete[] m_data;
        }

        auto operator = ( StringRef const &other ) noexcept -> StringRef& {
            delete[] m_data;
            m_data = nullptr;
            m_start = other.m_start;
            m_size = other.m_size;
            return *this;
        }