When incrementing or decrementing a variable, favor prefix operators over postfix operators if you do not need the value of the expression.
void foo(std::vector<int> intvec)
for (std::vector<int>::iterator it = intvec.begin(); it != intvec.end(); ++it)
The reason for this is that postfix operators (such as
) need to create a copy of the original variable. This copy is being used as a placeholder that later can be used as the value of the postfix expression. A prefix operator does not need to do that, as the value of a prefix increment or decrement expression is the value of the variable after the operation.
The cost of creating an additional temp might be trivial for integral types, but often ++/-- operators are defined for non-trivial types, and by their very nature they are being used in loop constructs.