C6281

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 C6281.

Warning 6281 - incorrect order of operations: relational operators have higher precedence than bitwise operators

This warning indicates a possible error in the operator precedence. This might produce incorrect results. You should check the precedence and use parentheses to clarify the intent. Relational operators (<, >, <=, >=, ==, != ) have higher precedence than bitwise operators (& | ^).

The following code generates this warning:

#include <stdlib.h>  
#define FORMAT 1  
#define TYPE 2  
  
void f(int input)  
{  
  if (FORMAT & TYPE != input)  
  {  
    // code...  
  }  
}  

The following code uses parentheses to correct this warning:

#include <stdlib.h>  
#define FORMAT 1  
#define TYPE 2  
  
void f(int input)  
{  
  if ((FORMAT & TYPE) != input)  
  {  
    // code...  
  }  
}  

Compiler Warning (level 3) C4554