FAQ: What the heck is a functionoid, and why would I use one? ←(in the new Super-FAQ)

 

It's in Section: Pointers to member functions:

• FAQ: Is the type of "pointer-to-member-function" different from "pointer-to-function"?
• FAQ: How do I pass a pointer-to-member-function to a signal handler, X event callback, system call that starts a thread/task, etc?
• FAQ: Why do I keep getting compile errors (type mismatch) when I try to use a member function as an interrupt service routine?
• FAQ: Why am I having trouble taking the address of a C++ function?
• FAQ: How can I avoid syntax errors when creating pointers to members?
• FAQ: How can I avoid syntax errors when calling a member function using a pointer-to-member-function?
• FAQ: How do I create and use an array of pointer-to-member-function?
• FAQ: How do I declare a pointer-to-member-function that points to a const member function?
• FAQ: What is the difference between the .* and ->* operators?
• FAQ: Can I convert a pointer-to-member-function to a void*?
• FAQ: Can I convert a pointer-to-function to a void*?
• FAQ: I need something like function-pointers, but with more flexibility and/or thread-safety; is there another way?
• FAQ: What the heck is a functionoid, and why would I use one? (this FAQ)
• FAQ: Can you make functionoids faster than normal function calls?
• FAQ: What's the difference between a functionoid and a functor?