我想让std::cout
打印一个UTF-8文字。这对于gcc来说似乎是一件容易的事,但对于Windows来说这是一个非常困难的任务。
我正在努力工作的代码是:
std::cout << "Ελληνικά Русский 你好";
环境:
要求:
main()
的开头添加一些设置代码我尝试过的:
#pragma execution_character_set("utf-8")
SetConsoleCP(CP_UTF8); SetConsoleOutputCP(CP_UTF8);
Use Unicode character set
项目物业没有任何帮助,没有StackOverflow答案解决了这个问题。
编辑
要使Unicode部分工作,请执行以下操作:
initStreams()
Use Unicode Character Set
/utf-8
选项不工作:
wprintf
cin
/ wcin
initStreams()
实施:
#include <cassert> // assert
#include <codecvt> // std::codecvt_utf8 (C++11)
#include <stdexcept> // std::exception
#include <streambuf> // std::basic_streambuf
#include <iostream> // std::cout, std::endl
#include <locale> // std::locale
#include <memory> // std::unique_ptr (C++11)
#undef UNICODE
#define UNICODE
#undef STRICT
#define STRING
#include <windows.h> // MultiByteToWideChar
class OutputForwarderBuffer : public std::basic_streambuf<char>
{
public:
using Base = std::basic_streambuf<char>;
using Traits = Base::traits_type;
using StreamBuffer = std::basic_streambuf<char>;
using WideStreamBuffer = std::basic_streambuf<wchar_t>;
using Base::int_type;
using Base::char_type;
OutputForwarderBuffer(
StreamBuffer& existingBuffer,
WideStreamBuffer* pWideStreamBuffer
)
: Base(existingBuffer)
, pWideStreamBuffer_(pWideStreamBuffer)
{
}
OutputForwarderBuffer(OutputForwarderBuffer const&) = delete;
void operator=(OutputForwarderBuffer const&) = delete;
protected:
std::streamsize xsputn(char const* s, std::streamsize n) override
{
if (n == 0) { return 0; }
int const sourceSize = static_cast<int>(n);
int const destinationSize = MultiByteToWideChar(CP_UTF8, 0, s, sourceSize, nullptr, 0);
wideCharBuffer_.resize(static_cast<size_t>(sourceSize));
int const nWideCharacters = MultiByteToWideChar(CP_UTF8, 0, s, sourceSize, &wideCharBuffer_[0], destinationSize);
assert(nWideCharacters > 0 && nWideCharacters == destinationSize);
return pWideStreamBuffer_->sputn(&wideCharBuffer_[0], destinationSize);
}
int_type overflow(int_type c) override
{
bool const cIsEOF = Traits::eq_int_type(c, Traits::eof());
int_type const failureValue = Traits::eof();
int_type const successValue = (cIsEOF ? Traits::not_eof(c) : c);
if (!cIsEOF) {
char_type const ch = Traits::to_char_type(c);
std::streamsize const nCharactersWritten = xsputn(&ch, 1);
return (nCharactersWritten == 1 ? successValue : failureValue);
}
return successValue;
}
private:
WideStreamBuffer* pWideStreamBuffer_;
std::wstring wideCharBuffer_;
};
void setUtf8Conversion(std::basic_ios<wchar_t>& stream)
{
stream.imbue(std::locale(std::locale::empty(), new std::codecvt_utf8_utf16<wchar_t>()));
}
bool isConsole(HANDLE streamHandle)
{
DWORD consoleMode;
return !!GetConsoleMode(streamHandle, &consoleMode);
}
bool isConsole(DWORD stdStreamId)
{
return isConsole(GetStdHandle(stdStreamId));
}
void initStreams()
{
SetConsoleCP(CP_UTF8);
SetConsoleOutputCP(CP_UTF8);
setUtf8Conversion(std::wcout);
setUtf8Conversion(std::wcerr);
setUtf8Conversion(std::wclog);
static OutputForwarderBuffer coutBuffer(*std::cout.rdbuf(), std::wcout.rdbuf());
static OutputForwarderBuffer cerrBuffer(*std::cerr.rdbuf(), std::wcerr.rdbuf());
static OutputForwarderBuffer clogBuffer(*std::clog.rdbuf(), std::wclog.rdbuf());
std::cout.rdbuf(&coutBuffer);
std::cerr.rdbuf(&cerrBuffer);
std::clog.rdbuf(&clogBuffer);
}
这是我要做的:
编辑:从Windows 10开始,您还需要:
setvbuf(stderr, NULL, _IOFBF, 1024); // on Windows 10+ we need buffering or console will get 1 byte at a time (screwing up utf-8 encoding)
setvbuf(stdout, NULL, _IOFBF, 1024);
不幸的是,这也意味着如果在下次冲洗之前完全填充缓冲区,仍有可能搞砸输出。正确的解决方案 - 在每个字符串发送到输出后手动刷新(endl
或fflush()
)(假设每个字符串小于1024)。如果只有MS支持行缓冲......