spdlog/include/c11log/details/fast_oss.h

#pragma once

#include<streambuf>
#include<string>
namespace c11log
{
namespace details
{

class str_devicebuf:public std::streambuf
{
public:
	str_devicebuf() = default;
	~str_devicebuf() = default;
	str_devicebuf(const str_devicebuf& other):std::streambuf(),_str(other._str) {}
	str_devicebuf& operator=(const str_devicebuf other)
	{
		if(this != &other)
			_str = other._str;
		return *this;
	}

	const std::string& str_ref() const {
		return _str;
	}

	void clear() {
		_str.clear();
	}

protected:
	virtual int sync() override {
		return 0;
	}

	virtual std::streamsize xsputn(const char_type* s, std::streamsize count) override {
		_str.append(s, static_cast<unsigned int>(count));
		return count;
	}

	virtual int_type overflow(int_type ch) override {
		if (ch != traits_type::eof())
			_str.append((char*)&ch, 1);
		return 1;
	}
private:
	std::string _str;
};

class fast_oss:public std::ostream
{
public:
	fast_oss():std::ostream(&_dev) {}
	~fast_oss() = default;
	fast_oss(const fast_oss& other):std::basic_ios<char>(), std::ostream(),_dev(other._dev) {}
	fast_oss& operator=(const fast_oss& other)
	{
		if(&other != this)
			_dev = other._dev;
		return *this;
	}

	const std::string& str_ref() const
	{
		return _dev.str_ref();
	}

	const std::string str() const
	{
		return _dev.str_ref();
	}

	void clear()
	{
		_dev.clear();
	}
private:
	str_devicebuf _dev;
};
}
}