Was this page helpful?
Your feedback about this content is important. Let us know what you think.
Additional feedback?
1500 characters remaining
Export (0) Print
Expand All
Expand Minimize
Important This document may not represent best practices for current development, links to downloads and other resources may no longer be valid. Current recommended version can be found here.

/U, /u (Undefine Symbols)

Undefine previously defined symbols. /U undefines the specified symbol. /u undefines all previously defined symbols.


/U[ ]symbol
/u

symbol

The symbol you want undefined.

Neither option can undefine symbols created with the #define directive.

Both options undefine the following Microsoft-specific macros.

Symbol Function

_CHAR_UNSIGNED

Default char type is unsigned. Defined when /J is specified.

_CPPRTTI

Defined for code compiled with the /GR (Enable Run-Time Type Information) option.

_CPPUNWIND

Defined for code compiled with the /EHsc (Enable Exception Handling) option.

_DLL

Defined when /MD is specified.

_M_IX86

Defined to 600, by default, for x86 targets.

_MSC_VER

For more information, see Predefined Macros.

_WIN32

Defined for applications for WIN32. Always defined.

_MT

Defined when /MD or /MT is specified.

To set this compiler option in the Visual Studio development environment

  1. Open the project's Property Pages dialog box. For details, see How to: Open Project Property Pages.

  2. Click the C/C++ folder.

  3. Click the Advanced property page.

  4. Modify the Undefine Preprocessor Definitions or Undefine All Preprocessor Definitions properties.

To set this compiler option programmatically

Community Additions

ADD
Show:
© 2015 Microsoft