prefix-operator

Because I've overloaded the operator++ for an iterator class template<typename T> typename list<T>::iterator& list<T>::iterator::operator++() { //stuff } But when I try to do list<int>::iterator IT; IT++; I get a warning about there being no postifx ++ , using prefix form. How can I specifically overload the prefix/postifx forms? Daniel Earwicker Write a version of the same operator overload, but give it a parameter of type int . You don't have to do anything with that parameter's value. If you're interested in some history of how this syntax was arrived out, there's a snippet of it here .

In GHCi: Prelude> (+3) 2 5 Prelude> (*3) 2 6 Prelude> (/3) 2 0.6666666666666666 Prelude> (-3) 2 No instance for (Num (t -> t1)) arising from the literal 3' at <interactive>:1:2 Possible fix: add an instance declaration for (Num (t -> t1)) In the expression: 3 In the expression: (- 3) 2 In the definition of it': it = (- 3) 2 How can I correct the last one to make it return -1? Haskell's grammar doesn't allow you to use - like that. Use the subtract function instead: (subtract 3) 2 Travis Brown As a footnote to grddev's answer , here's the relevant paragraph from the Haskell 98 Report : The