使用c++11标准库转换字符编码

柔情只为你懂 2022-03-19 16:45 200阅读 0赞

#include <stdio.h>
    #include <locale>
    #include <codecvt>
    
    const std::string ws2s( const std::wstring& src )
    {
    	std::locale sys_locale("");
    
    	const wchar_t* data_from = src.c_str();
    	const wchar_t* data_from_end = src.c_str() + src.size();
    	const wchar_t* data_from_next = 0;
    
    	int wchar_size = 4;
    	char* data_to = new char[(src.size() + 1) * wchar_size];
    	char* data_to_end = data_to + (src.size() + 1) * wchar_size;
    	char* data_to_next = 0;
    
    	memset( data_to, 0, (src.size() + 1) * wchar_size );
    
    	typedef std::codecvt<wchar_t, char, mbstate_t> convert_facet;
    	mbstate_t out_state = 0;
    	auto result = std::use_facet<convert_facet>(sys_locale).out(
    		out_state, data_from, data_from_end, data_from_next,
    		data_to, data_to_end, data_to_next );
    	if( result == convert_facet::ok )
    	{
    		std::string dst = data_to;
    		delete[] data_to;
    		return dst;
    	}
    	else
    	{
    		printf( "convert error!\n" );
    		delete[] data_to;
    		return std::string("");
    	}
    }
    
    const std::wstring s2ws( const std::string& src )
    {
    	std::locale sys_locale("");
    		
    	const char* data_from = src.c_str();
    	const char* data_from_end = src.c_str() + src.size();
    	const char* data_from_next = 0;
    
    	wchar_t* data_to = new wchar_t[src.size() + 1];
    	wchar_t* data_to_end = data_to + src.size() + 1;
    	wchar_t* data_to_next = 0;
    
    	wmemset( data_to, 0, src.size() + 1 );
    
    	typedef std::codecvt<wchar_t, char, mbstate_t> convert_facet;
    	mbstate_t in_state = 0;
    	auto result = std::use_facet<convert_facet>(sys_locale).in(
    		in_state, data_from, data_from_end, data_from_next,
    		data_to, data_to_end, data_to_next );
    	if( result == convert_facet::ok )
    	{
    		std::wstring dst = data_to;
    		delete[] data_to;
    		return dst;
    	}
    	else
    	{
    		printf( "convert error!\n" );
    		delete[] data_to;
    		return std::wstring(L"");
    	}
    }
    
    const std::string ws2utf8( const std::wstring& src )
    {
    	std::wstring_convert<std::codecvt_utf8<wchar_t>> conv;
    	return conv.to_bytes( src );
    }
    
    const std::wstring utf8_2_ws( const std::string& src )
    {
    	std::wstring_convert<std::codecvt_utf8<wchar_t> > conv;
    	return conv.from_bytes( src );
    }

http://it.cppreference.com/w/cpp/locale/wstring_convert

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