C++ Primer Plus

The Range-Based for Loop (C++11)

The range-based for loop, mentioned in Chapter 5, “Loops and Relational Expressions,” is designed to work with the STL. To review, here’s the first example from Chapter 5:

double prices[5] = {4.99, 10.99, 6.87, 7.99, 8.49};for (double x : prices)    cout << x << std::endl;

The contents of the parentheses for the for loop declare a variable of the type stored in a container and then the name of the container. Next, the body of the loop uses the named variable to access each container element in turn. Consider, for instance, this statement from Listing 16.9:

for_each(books.begin(), books.end(), ShowReview);

It can be replaced with the following range-based for loop:

for (auto x : books) ShowReview(x);

The compiler ...