Can I use bitwise operators instead of logical ones?

Question

Bitwise operators work on bits, logical operators evaluate boolean expressions. As long as expressions return bool, why don\'t we use bitwise operators instead

Answer 1

There is a distinct difference between || and |.

Unlike most other operators in the language, the logical || operator explicitly specifies the order of evaluation. The first operand of || must be evaluated before the second. The second need not be evaluated at all.

This is fundamentally different from | which behaves as most operators: the order of evaluation is unspecified, and both expressions will be evaluated. Even in the case where one operand is found to be non-zero, the other operand will still be evaluated for side effects.

Meaning that code like f1() || f2() will always evaluate to this pseudo code:

if(f1() != 0)
{
  f2();
}

whereas f1() | f2() will execute both functions, in an unspecified order that the programmer can't know.

This also means that statements like "|| is faster than |" are naive. Sure, in case of || the second operand isn't necessarily evaluated, but this comes at the cost of a branch, as well as restrictions for how the compiler is allowed to re-order the expression. Which operator that is generally faster isn't obvious.