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For another example posts on functors (function objects) see here . A functor is an instance of a C++ class that has the operator() defined. One big advantage of functors is that when you define the operator() in C++ classes you not only get objects that can act like functions, but can also store state as well.

Some code samples I have collated in the sample below, that demonstrate how boost::function can be assigned with functors, ordinary functions, class member functions and overloaded class member functions respectively. [code language="cpp"] #include <iostream> #include <boost/function.hpp> #include <boost/bind.hpp> using namespace std; // Class for example 1: functors class int_div { public: float operator()(int x, int y) const { return ((float)x)/y; }; }; // Class for example 2: : accessing functions float average( int values[], int n ) { int sum = 0; for (int i = 0; i < n; i++) sum += values[ i ]; return (float) sum / n; } // Class for example 3: accessing class members class DoStuff { public: void DoThis() { std::cout << "Do this" << std::endl; } void DoThat( std::string message ) { std::cout << message << std::endl; } }; // Class for example 4: overloaded class members class Overload { p...

This post assumes that the boost libraries have been downloaded and extracted to the directory of your choice. See this previous posting for more details on how to download and extract the Boost libraries. Open Cygwin and cd to the location where your Boost libraries have been installed. For Windows directories with white spaces please enclose it in quotes, eg: $ cd "C:\Program Files\boost_1_46_1" Check to see that the boost/ folder lives at this location using $ ls : If so, run the bootstrap: $ ./bootstrap.sh –prefix=boost/ Then run the bjam executable (takes a while) $ ./bjam And run bjam installer (takes a very long while): $ ./bjam install After this has completed you will find that within the boost/ folder, three other folders have been created, namely bin , include and lib . Recursively copy these 3 folders to the /usr/local/ destination: $ cp -r boost/bin /usr/local/ $ cp -r boost/include /usr/local/ $ cp -r boost/lib /usr/local/ ...

This post takes a look at using boost::bind as a means of calling class member functions in an efficient and generic way. It basically summarizes what has already been said at Björn Karlsson's excellent Informit article . Since I found the post useful, I thought it worth reproducing here, using the same status class but containing all the examples and approaches he describes in one program.

1. Install the Boost libraries from the command line First try the following $ sudo apt-get install libboost* You may get an error message similar to the following, like I did: