Is there a utility in Boost which determines at compile time whether or not a given type meets the most basic requirements for an iterator, without generating an error if the test fails? (This last part is crucial, so concept checks are insufficient.) I recently needed something like this, and I couldn't seem to find it in any of the libraries, so I went ahead and wrote a template metafunction called 'is_iterator' which gets the job done. It uses the same SFINAE techniques as the enable_if library. The declaration looks like this: template <typename T> struct is_iterator; The 'is_iterator' struct template is a model of the "integral constant expression" concept. Thus, 'is_iterator<T>::value' evaluates to true if-and-only-if type T defines iterator traits as well as overloaded operators with the following signatures: boost::iterator_reference<T>::type operator*(void) const; boost::iterator_pointer<T>::type operator->(void) const; T & operator++(void); T operator++(int); These seem to be the minimal requirements (i.e. Readable and Incrementable) according to the New Iterator Concepts. Ideally, T would also have to be a Copy Constructible type, but I don't know of a reliable way to detect this. Originally, i needed the ability to determine at compile time whether or not a given type meets the requirements for a Readable Lvalue iterator. The 'is_readable_iterator' and 'is_lvalue_iterator' template metafunctions work fine for this purpose, except that they both generate an error when passed a template argument that is not an iterator at all. Assuming I'm correct in stating that a utility like 'is_iterator' does not already exist in Boost, is there any interest in such a utility? Thanks, Alex