Synopsis

Some expressions, such as x & x and x | x, are redundant.

Enabled by default

No

Severity/Certainty

Low/Medium

Full description

Using one or more variable does not result in a change in that variable, or another variable, or some other side-effect. Giving two identical operands to a bitwise OR operator, for example, yields nothing, because the result is equal to the original operands. This might indicate that one of the variables is not intended to be used where it is used. This use of the operator is redundant.

Coding standards

This check does not correspond to any coding standard rules.

Code examples

The following code example fails the check and will give a warning:

void example(int x) {
  x = x;
}

The following code example passes the check and will not give a warning about this issue:

void example(int x) {
  x = x ^ x;  //OK - x is modified
}