Chapter 11. Generic Algorithms
| CONTENTS
The library containers define a surprisingly small set of operations. Rather than adding lots of functionality to the containers, the library instead provides a set of algorithms, most of which are independent of any particular container type. These algorithms are "generic:" They operate on different types of containers and on elements of various types. The generic algorithms, and a more detailed look at iterators, form the subject matter of this chapter. The standard containers define few operations. For the most part they allow us to add and remove elements; to access the first or last element; to obtain and in some cases reset the size of the container; and to obtain iterators to the first and one past the last element. We can imagine many other useful operations one might want to do on the elements of a container. We might want to sort a sequential container, or find a particular element, or find the largest or smallest element, and so on. Rather than define each of these operations as members of each container type, the standard library defines a set of generic algorithms: "algorithms" because they implement common operations; and "generic" because they operate across multiple container typesnot only library types such as vector or list, but also the built-in array type, and, as we shall see, over other kinds of sequences as well. The algorithms also can be used on container types we might define ourselves, as long as our types conform to the standard library conventions. Most of the algorithms operate by traversing a range of elements bounded by two iterators. Typically, as the algorithm traverses the elements in the range, it operates on each element. The algorithms obtain access to the elements through the iterators that denote the range of elements to traverse. |
EAN: 2147483647
Pages: 223