Hi, I'd like to write the "Preferred syntax" of a signal while including a header for a fixed number of parameters. This works for boost::function, but not for boost::signal. Surprisingly, it seems that signal1.hpp does only generate a signal1 template, in contrast to function1.hpp. :[ Couldn't that be aligned to boost::function? #include <boost/function/function1.hpp> typedef boost::function1<void, void> F1; // compiles typedef boost::function<void (void)> F2; // compiles #include <boost/signals/signal1.hpp> typedef boost::signal1<void, void> S1; // compiles typedef boost::signal<void (void)> S2; // does not compile -- David