compiler-warning-level-1-c4806.md

description	title	ms.date	f1_keywords	helpviewer_keywords	ms.assetid
Learn more about: Compiler Warning (level 1) C4806	Compiler Warning (level 1) C4806	11/04/2016	C4806	C4806	79eb74cd-b925-4b5b-84e1-8ae6f33e38b3

Compiler Warning (level 1) C4806

'operation' : unsafe operation: no value of type 'type' promoted to type 'type' can equal the given constant

This message warns against code such as b == 3, where b has type bool. The promotion rules cause bool to be promoted to int. This is legal, but it can never be true. The following sample generates C4806:

// C4806.cpp
// compile with: /W1
int main()
{
   bool b = true;
   // try..
   // int b = true;

   if (b == 3)   // C4806
   {
      b = false;
   }
}