C++ Primer, Fifth Edition

16.4.1. Writing a Variadic Function Template

In § 6.2.6 (p. 220) we saw that we can use an initializer_list to define a function that can take a varying number of arguments. However, the arguments must have the same type (or types that are convertible to a common type). Variadic functions are used when we know neither the number nor the types of the arguments we want to process. As an example, we’ll define a function like our earlier error_msg function, only this time we’ll allow the argument types to vary as well. We’ll start by defining a variadic function named print that will print the contents of a given list of arguments on a given stream. ...