spdlog/include/c11log/details/fast_oss.h
2014-03-16 20:48:37 +02:00

87 lines
1.7 KiB
C++

#pragma once
// Fast ostringstream like supprt which return its string by ref and nothing more
#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) = 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:
virtual int sync() override
{
return 0;
}
virtual std::streamsize xsputn(const char_type* s, std::streamsize count) override
{
auto ssize = _str.size();
auto cap_left = _str.capacity() - ssize;
if(cap_left < static_cast<std::size_t>(count))
_str.reserve(ssize + count + 128);
_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) = 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;
};
}
}