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CW2WEX Class

  • Article

This class is used by the string conversion macros CW2TEX and CT2WEX, and the typedef CW2W.

Important

This class and its members cannot be used in applications that execute in the Windows Runtime.

Syntax

template <int t_nBufferLength = 128>
class CW2WEX

Parameters

t_nBufferLength
The size of the buffer used in the translation process. The default length is 128 bytes.

Members

Public Constructors

Name Description
CW2WEX::CW2WEX The constructor.
CW2WEX::~CW2WEX The destructor.

Public Operators

Name Description
CW2WEX::operator LPWSTR Conversion operator.

Public Data Members

Name Description
CW2WEX::m_psz The data member that stores the source string.
CW2WEX::m_szBuffer The static buffer, used to store the converted string.

Remarks

Unless extra functionality is required, use CW2TEX, CT2WEX, or CW2W in your code.

This class contains a fixed-size static buffer which is used to store the result of the conversion. If the result is too large to fit into the static buffer, the class allocates memory using malloc, freeing the memory when the object goes out of scope. This ensures that, unlike text conversion macros available in previous versions of ATL, this class is safe to use in loops and that it won't overflow the stack.

If the class tries to allocate memory on the heap and fails, it will call AtlThrow with an argument of E_OUTOFMEMORY.

By default, the ATL conversion classes and macros use the current thread's ANSI code page for the conversion.

The following macros are based on this class:

  • CW2TEX

  • CT2WEX

The following typedef is based on this class:

  • CW2W

For a discussion of these text conversion macros, see ATL and MFC String Conversion Macros.

Example

See ATL and MFC String Conversion Macros for an example of using these string conversion macros.

Requirements

Header: atlconv.h

CW2WEX::CW2WEX

The constructor.

CW2WEX(LPCWSTR psz, UINT nCodePage) throw(...);
CW2WEX( LPCWSTR  psz) throw(...);

Parameters

psz
The text string to be converted.

nCodePage
The code page. Not used in this class.

Remarks

Creates the buffer required for the translation.

CW2WEX::~CW2WEX

The destructor..

~CW2WEX() throw();

Remarks

Frees the allocated buffer.

CW2WEX::m_psz

The data member that stores the source string.

LPWSTR m_psz;

CW2WEX::m_szBuffer

The static buffer, used to store the converted string.

wchar_t m_szBuffer[t_nBufferLength];

CW2WEX::operator LPWSTR

Cast operator.

operator LPWSTR() const throw();

Return Value

Returns the text string as type LPWSTR.

See also

CA2AEX Class
CA2CAEX Class
CA2WEX Class
CW2AEX Class
CW2CWEX Class
Class Overview