Compiler Error C2004

The new home for Visual Studio documentation is Visual Studio 2017 Documentation on docs.microsoft.com.

The latest version of this topic can be found at Compiler Error C2004.

expected 'defined(id)'

An identifier must appear in the parentheses following the preprocessor keyword.

This error can also be generated as a result of compiler conformance work that was done for Visual Studio .NET 2003: missing parenthesis in preprocessor directive. If the closing parenthesis is missing from a preprocessor directive, the compiler will generate an error.

The following sample generates C2004:

// C2004.cpp  
// compile with: /DDEBUG  
#include <stdio.h>  
  
int main()   
{  
    #if defined(DEBUG   // C2004  
        printf_s("DEBUG defined\n");  
    #endif  
}  

Possible resolution:

// C2004b.cpp  
// compile with: /DDEBUG  
#include <stdio.h>  
  
int main()   
{  
    #if defined(DEBUG)  
        printf_s("DEBUG defined\n");  
    #endif  
}