boost::locale::conv:: 字符编码转换

相关字符集转换函数功能摘要：std::string boost::locale::conv::between(char const * begin,  char const * end,  std::string const & to_encoding,  std::string const & from_encoding,  method_type how = default_method  )  Convert a text in range [begin,end) to to_encoding from from_encodingstd::string boost::locale::conv::between(char const * text,  std::string const & to_encoding,  std::string const & from_encoding,  method_type how = default_method  ) [inline]Convert a text to to_encoding from from_encodingstd::string boost::locale::conv::between(std::string const & text,  std::string const & to_encoding,  std::string const & from_encoding,  method_type how = default_method  ) [inline]Convert a text to to_encoding from from_encodingtemplate<typename CharType >std::string boost::locale::conv::from_utf(CharType const * begin,  CharType const * end,  std::string const & charset,  method_type how = default_method  )  convert UTF text in range [begin,end) to a text encoded with charset according to policy howtemplate<typename CharType >std::string boost::locale::conv::from_utf(CharType const * begin,  CharType const * end,  std::locale const & loc,  method_type how = default_method  )  convert UTF text in range [begin,end) to a text encoded according to locale loc according to policy howNote:throws std::bad_cast if the loc does not have info facet installedtemplate<typename CharType >std::string boost::locale::conv::from_utf(std::basic_string< CharType > const & text,  std::string const & charset,  method_type how = default_method  )  Convert a text from charset to UTF stringtemplate<typename CharType >std::string boost::locale::conv::from_utf(CharType const * text,  std::string const & charset,  method_type how = default_method  )  Convert a text from UTF to charsettemplate<typename CharType >std::string boost::locale::conv::from_utf(std::basic_string< CharType > const & text,  std::locale const & loc,  method_type how = default_method  )  Convert a text in UTF to locale encoding given by locNote:throws std::bad_cast if the loc does not have info facet installedtemplate<typename CharType >std::string boost::locale::conv::from_utf(CharType const * text,  std::locale const & loc,  method_type how = default_method  )  Convert a text in UTF to locale encoding given by locNote:throws std::bad_cast if the loc does not have info facet installedtemplate<typename CharType >std::basic_string<CharType> boost::locale::conv::to_utf(char const * begin,  char const * end,  std::string const & charset,  method_type how = default_method  )  convert string to UTF string from text in range [begin,end) encoded with charset according to policy howtemplate<typename CharType >std::basic_string<CharType> boost::locale::conv::to_utf(char const * begin,  char const * end,  std::locale const & loc,  method_type how = default_method  )  convert string to UTF string from text in range [begin,end) encoded according to locale loc according to policy howNote:throws std::bad_cast if the loc does not have info facet installedtemplate<typename CharType >std::basic_string<CharType> boost::locale::conv::to_utf(std::string const & text,  std::string const & charset,  method_type how = default_method  )  convert a string text encoded with charset to UTF stringtemplate<typename CharType >std::basic_string<CharType> boost::locale::conv::to_utf(char const * text,  std::string const & charset,  method_type how = default_method  )  Convert a text from charset to UTF stringtemplate<typename CharType >std::basic_string<CharType> boost::locale::conv::to_utf(std::string const & text,  std::locale const & loc,  method_type how = default_method  )  Convert a text in locale encoding given by loc to UTFNote:throws std::bad_cast if the loc does not have info facet installedtemplate<typename CharType >std::basic_string<CharType> boost::locale::conv::to_utf(char const * text,  std::locale const & loc,  method_type how = default_method  )  Convert a text in locale encoding given by loc to UTFNote:throws std::bad_cast if the loc does not have info facet installedtemplate<typename CharOut , typename CharIn >std::basic_string<CharOut> boost::locale::conv::utf_to_utf(CharIn const * begin,  CharIn const * end,  method_type how = default_method  )  Convert a Unicode text in range [begin,end) to other Unicode encodingtemplate<typename CharOut , typename CharIn >std::basic_string<CharOut> boost::locale::conv::utf_to_utf(CharIn const * str,  method_type how = default_method  )  Convert a Unicode NUL terminated string str other Unicode encodingtemplate<typename CharOut , typename CharIn >std::basic_string<CharOut> boost::locale::conv::utf_to_utf(std::basic_string< CharIn > const & str,  method_type how = default_method  )  Convert a Unicode string str other Unicode encoding

简单示例：
1、between把 source 这个字串从BIG5 转换到 UTF-8：

string source = "BIG5字符串";  string s = boost::locale::conv::between( source, "UTF-8", "BIG5" ); 

2、to_utf可以输出 string ，也可以输出成 wstring。像下面的例子，就是把 sSource 这个 BIG-5 编码的字串，依序转换成 wstring 和 string 的字串。

string sSource = "BIG-5字符串";  wstring ws = boost::locale::conv::to_utf<wchar_t>( sSource, "BIG5" );  string  ss = boost::locale::conv::to_utf<char>( sSource, "BIG5" );  

3、from_utf 是把 UTF 字串（string 或wstring）、转换为特定编码的字串用的，他可以转换string 或wstring 的字串，但是输出一定是string。
下面的例子，就是把 sSource 和 wSource 这两个 UTF 字串，都转换成 BIG-5 的 string 字串。

string  sSource =  "字符串";  wstring wSource = L"...";  string  ss1 = boost::locale::conv::from_utf( wSource, "BIG5" );  string  ss2 = boost::locale::conv::from_utf( sSource, "BIG5" );  

4、utf_to_utf的目的，是在 UTF 的 string 字串和 wstring 字串之间做转换，下面的例子，就是把类型是 string 的 sSource 转换成 wstring、并把类型是 wstring 的 wSource 转换成 string

string  sSource =  "...";  wstring wSource = L"...";  wstring wStr = boost::locale::conv::utf_to_utf<wchar_t>( sSource );  string  sStr = boost::locale::conv::utf_to_utf<char>( wSource );