CS202
6- ‹#›
Increment and Decrement
nTo distinguish the prefix from the postfix forms,
the C++ standard has added an unused argument (int) to represent the postfix signature.
nSince these operators should modify the current object,they should not be const members!
nPrefix: residual vlaue is an lvalue
counter &
counter::operator ++ () { .... //body }
counter &
counter::operator -- () { .... //body }
nPostfix: residual
value is an rvalue, different than the current object!
counter counter::operator
++ (int) { .... //body }
counter counter::operator
-- (int) { .... //body }