/U, /u (Undefine Symbols)
Undefine previously defined symbols. /U undefines the specified symbol. /u undefines all previously defined symbols.
/U[ ]symbol
/u
Arguments
- symbol
The symbol you want undefined.
Remarks
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
Open the project's Property Pages dialog box. For details, see How to: Open Project Property Pages.
Click the C/C++ folder.
Click the Advanced property page.
Modify the Undefine Preprocessor Definitions or Undefine All Preprocessor Definitions properties.