I've been using Boost increasingly in my work and am loving it. There are two utilities I've beens surprised Boost lacks: First, I would like to see an "insert_const" metafunction that would work like this: template <typename T> struct insert_const<T*> { typedef typename add_const<T>::type* type; }; That is, it would insert a const into the thing pointed to by a pointer type. (I am interfacing with a C-style interface to C++ code. The interface passes around "pFoo" and "pBar" – pointers to Foos and Bars. I've used the above metafunction to create typedefs for const_pFoo and const_pBar, like so: typedef typename<insert_const<pFoo> >::type const_pFoo; typedef typename<insert_const<pBar> >::type const_pBar; Would this be a desirable addition? Second, I often find myself wanting to iterate over every element in a nested container. For example, a vector<list<double> >. I've made a partly-functional nested_iterator class that models ForwardIterator. My implementation defaults to use ".begin()" and ".end()" to find the inner range, but can be adapted with a function object. Has anyone considered adding this sort of iterator to Boost? —Ben