This documentation is archived and is not being maintained.

Compiler Warning (level 1) C4555

Error Message

expression has no effect; expected expression with side-effect

This warning informs you when an expression has no effect.

This warning is off by default. See Compiler Warnings That Are Off by Default for more information.

For example:

// C4555.cpp
// compile with: /W1
#pragma warning(default:4555)

void func1()
   1;   // C4555

void func2()
   int x;
   x;   // C4555

int main()