Editing Multiple dispatch (section)

=== Data types ===
When working with languages that can discriminate [[data type]]s at [[compile time]], selecting among the alternatives can occur then. The act of creating such alternative functions for compile time selection is usually referred to as [[Function overloading|overloading]] a function.

In programming languages that defer data type identification until run time (i.e., [[late binding]]), selection among alternative functions must occur then, based on the dynamically determined types of function arguments. Functions whose alternative implementations are selected in this manner are referred to most generally as ''multimethods''.

There is some run-time cost associated with dynamically dispatching function calls. In some languages,{{Citation needed|date=December 2007}} the distinction between overloading and multimethods can be blurred, with the compiler determining whether compile time selection can be applied to a given function call, or whether slower run time dispatch is needed.