Re: stl::map: return default value without inserting a new element?

Not sure I can suggest an improvement using iterators however I can
suggest one minor improvement to getOrZero:

template < class K, class V, class C, class A>
const V&
getOrZero (
  std::map<K,V,C,A> const & m
, K const & k
) {
 static const V default;
  typename std::map<K,V,C,A>::const_iterator i = m.find(k) ;
  return i != m.end() ? i->second : default ;
}

We no longer have to make a (possibly RVO optimized) copy of the
container element if we don't need a copy and if getOrZero is called many
times we only ever create one default element.

/Leigh