What is the purpose of template functions?

Template functions provide the ability to write a single function that can accept different types of inputs and produce different types of output, while still using the same logic. For example, a template function can accept an int, long, or float and perform the same logic on any of the three types of parameters. The compiler ensures that the template function will make sense when compiled with a particular type. This was an early attempt at polymorphism (using the same code on different types of objects), and has since been superseded in newer languages using objects and inheritance.