WideCharToMultiByte() and MultiByteToWideChar() added

This commit is contained in:
Simon Rozman 2016-05-17 11:17:13 +02:00
parent 6899f2a7b0
commit a1a7ca6dac

View File

@ -573,6 +573,60 @@ inline LSTATUS RegLoadMUIStringW(_In_ HKEY hKey, _In_opt_ LPCWSTR pszValue, _Out
#endif #endif
///
/// Maps a UTF-16 (wide character) string to a std::string. The new character string is not necessarily from a multibyte character set.
///
/// \sa [WideCharToMultiByte function](https://msdn.microsoft.com/en-us/library/windows/desktop/dd374130.aspx)
///
template<class _Elem, class _Traits, class _Ax>
inline int WideCharToMultiByte(_In_ UINT CodePage, _In_ DWORD dwFlags, _In_z_count_(cchWideChar) LPCWSTR lpWideCharStr, _In_ int cchWideChar, _Out_ std::basic_string<_Elem, _Traits, _Ax> &sMultiByteStr, _In_opt_ LPCSTR lpDefaultChar, _Out_opt_ LPBOOL lpUsedDefaultChar)
{
_Elem szStackBuffer[WINSTD_STACK_BUFFER_BYTES/sizeof(_Elem)];
// Try to convert to stack buffer first.
int cch = ::WideCharToMultiByte(CodePage, dwFlags, lpWideCharStr, cchWideChar, szStackBuffer, _countof(szStackBuffer), lpDefaultChar, lpUsedDefaultChar);
if (cch) {
// Copy from stack.
sMultiByteStr.assign(szStackBuffer, cch);
} else if (::GetLastError() == ERROR_INSUFFICIENT_BUFFER) {
// Query the required output size. Allocate buffer. Then convert again.
cch = ::WideCharToMultiByte(CodePage, dwFlags, lpWideCharStr, cchWideChar, NULL, 0, lpDefaultChar, lpUsedDefaultChar);
auto szBuffer = std::unique_ptr<_Elem[]>(new _Elem[cch]);
cch = ::WideCharToMultiByte(CodePage, dwFlags, lpWideCharStr, cchWideChar, szBuffer.get(), cch, lpDefaultChar, lpUsedDefaultChar);
sMultiByteStr.assign(szBuffer.get(), cch);
}
return cch;
}
///
/// Maps a character string to a UTF-16 (wide character) std::wstring. The character string is not necessarily from a multibyte character set.
///
/// \sa [WideCharToMultiByte function](https://msdn.microsoft.com/en-us/library/windows/desktop/dd374130.aspx)
///
template<class _Elem, class _Traits, class _Ax>
inline int MultiByteToWideChar(_In_ UINT CodePage, _In_ DWORD dwFlags, _In_z_count_(cbMultiByte) LPCSTR lpMultiByteStr, _In_ int cbMultiByte, _Out_ std::basic_string<_Elem, _Traits, _Ax> &sWideCharStr)
{
_Elem szStackBuffer[WINSTD_STACK_BUFFER_BYTES/sizeof(_Elem)];
// Try to convert to stack buffer first.
int cch = ::MultiByteToWideChar(CodePage, dwFlags, lpMultiByteStr, cbMultiByte, szStackBuffer, _countof(szStackBuffer));
if (cch) {
// Copy from stack.
sWideCharStr.assign(szStackBuffer, cch);
} else if (::GetLastError() == ERROR_INSUFFICIENT_BUFFER) {
// Query the required output size. Allocate buffer. Then convert again.
cch = ::MultiByteToWideChar(CodePage, dwFlags, lpMultiByteStr, cbMultiByte, NULL, 0);
auto szBuffer = std::unique_ptr<_Elem[]>(new _Elem[cch]);
cch = ::MultiByteToWideChar(CodePage, dwFlags, lpMultiByteStr, cbMultiByte, szBuffer.get(), cch);
sWideCharStr.assign(szBuffer.get(), cch);
}
return cch;
}
/// @} /// @}