Editing Ad hoc polymorphism (section)

==Example==
Imagine an operator <code>+</code> that may be used in the following ways:
# <code>1 + 2 = 3</code>
# <code>3.14 + 0.0015 = 3.1415</code>
# <code>1 + 3.7 = 4.7</code>
# <code>[1, 2, 3] + [4, 5, 6] = [1, 2, 3, 4, 5, 6]</code>
# <code>[true, false] + [false, true] = [true, false, false, true]</code>
# <code>"bab" + "oon" = "baboon"</code>
To handle these six function calls, four different pieces of code are needed (or three, if strings are considered to be lists of characters):
* In the first case, [[integer (computer science)|integer]] addition must be invoked.
* In the second and third cases, [[floating point|floating-point]] addition must be invoked (with [[type promotion]], or [[type coercion]], in the third case).
* In the fourth and fifth cases, [[List (computing)|list]] [[concatenation]] must be invoked.
* In the last case, [[literal string|string]] concatenation must be invoked.
Thus, the name <code>+</code> actually refers to three or four completely different functions. This is an example of ''[[Overloading (programming)|overloading]]'' or more specifically, ''[[operator overloading]]''.

Note the ambiguity in the string types used in the last case. Consider <code>"123" + "456"</code> in which the programmer might ''naturally'' assume addition rather than concatenation. They may expect <code>"579"</code> instead of <code>"123456"</code>. Overloading can therefore provide different meaning, or semantics, for an operation, as well as differing implementations.