#pragma once // Fast ostringstream like supprt which return its string by ref and nothing more #include #include namespace c11log { namespace details { class str_devicebuf:public std::streambuf { public: str_devicebuf() = default; ~str_devicebuf() = default; str_devicebuf(const str_devicebuf& other) = delete; str_devicebuf(str_devicebuf&& other) = delete; str_devicebuf& operator=(const str_devicebuf&) = delete; str_devicebuf& operator=(str_devicebuf&&) = delete; const std::string& str_ref() const { return _str; } void reset_str() { _str.clear(); } protected: int sync() override { return 0; } // copy the give buffer into the accumulated string. // reserve initially 128 bytes which should be enough for common log lines std::streamsize xsputn(const char_type* s, std::streamsize count) override { if(_str.capacity() < k_initial_reserve) { _str.reserve(k_initial_reserve); } _str.append(s, static_cast(count)); return count; } int_type overflow(int_type ch) override { if (ch != traits_type::eof()) xsputn((char*)&ch, 1); return 1; } private: std::string _str; static constexpr std::streamsize k_initial_reserve = 128; }; class fast_oss:public std::ostream { public: fast_oss():std::ostream(&_dev) {} ~fast_oss() = default; fast_oss(const fast_oss& other) = delete; fast_oss(fast_oss&& other) = delete; fast_oss& operator=(const fast_oss& other) = delete; const std::string& str_ref() const { return _dev.str_ref(); } void reset_str() { _dev.reset_str(); } private: str_devicebuf _dev; }; } }