I have written a class that uses named parameters in the constructor because there's like 10 parameters and too often you just want to replace one. Exactly the reason to use them in other words. Unfortunately, I also use the boost::signals2 library. It also apparently uses this library because I keep running into problems where BOOST_PARAMETER_MAX_ARITY has already been set. Even if I undefine it and redefine it to what I need I have problems when it says I've supplied too many template parameters. Wouldn't it be reasonable to expect that this value is undefined at the end of boost headers that use it? At least in 1.42, signals2 does not do so. What is a reasonable approach to dealing with conflicts like this? I've taken to just moving my include up the stack of includes whenever I run into the problem. -- http://crazyeddiecpp.blogspot.com/