Why would one use the |= operator on a boolean value in C#?

Question

Example:

We found this is some vendor written code and we're trying to figure out why they'd do this.

bool tmp = false;  if (somecase)    tmp = true;  if (someOtherCase)    tmp |= true;    

Answer 1

For no good reason at all. A boolean value |= true will always be true. This is someone trying to be fancy, or forgetting boolean logic =)

Change it to tmp = true;.

Answer 2

Perhaps one of the boolean literals used to be a variable, and they just didn't think to change the operator when they changed the operand. Obviously the logic is equivalent.

More likely, they were thinking that in the second case, they want to retain the result of evaluating the first "if" condition. Of course, that's false reasoning.

A simpler equivalent statement:

bool tmp = somecase | someOtherCase; 

EDIT

As pickypg notes, this statement could be confusing, since most people don't expect | with boolean values, and many won't notice it, or won't think about the implications for side effects. The best way to be explicit (if indeed there are side effects) would be minitech's solution: just change the |= to =.

Or, if there are no side effects to the someOtherCase expression, use Jakub Konecki's solution : someCase || someOtherCase.