[Boost-users] style: overloading vs default parameters

Is there any particular reason why at least some boost code uses default parameters. IME, I've found the using overloading is preferable. For example, when using boost::bind, one would have to explicitly give the default parameters whereas one wouldn't if overloading were used. Also, using overloading rather than default parameters when a new function interface is needed can potentially break less client code (eg code that uses the type of the function won't break if overloading were used). Given this, I'd like to hear some arguments for using default arguments over overloading (outside of constructors, of course, where one may not have much of a choice). Thanks, Noel