[boost] [extension] Check if basic_type_map is empty

From: Boris (boriss_at_[hidden])
Date: 2008-08-20 17:42:03

When a library is loaded the return type of shared_library::open() or  
shared_library::is_open() can be used to detect whether the library was  
loaded successfully. When shared_library::call() is called the return type  
can be used to detect whether the exported map function could be called.  
But is there another function like is_open() which could be called  
afterwards to check if the map function was called successfully? The  
datatype basic_type_map only provides get() and no empty(). It would be  
required to call get() first and operate on the returned std::map type to  
see if it contains any factories?

Boris