Generic programming vs. Metaprogramming

Question

What exactly is the difference? It seems like the terms can be used somewhat interchangeably, but reading the wikipedia entry for Objective-c, I came across:

Answer 1

I would roughly define metaprogramming as "writing programs to write programs" and generic programming as "using language features to write functions, classes, etc. parameterized on the data types of arguments or members".

By this standard, C++ templates are useful for both generic programming (think vector, list, sort...) and metaprogramming (think Boost and e.g. Spirit). Furthermore, I would argue that generic programming in C++ (i.e. compile-time polymorphism) is accomplished by metaprogramming (i.e. code generation from templated code).