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For example, basic_fstream<CharT,Traits> refers to the generic class template that implements input/output operations on file streams. It is usually used as fstream which is an alias for basic_fstream<char,char_traits<char>> , or, in other words, basic_fstream working on characters of type char with the default character operation set.
The C++ Standard Library provides several generic containers, functions to use and manipulate these containers, function objects, generic strings and streams (including interactive and file I/O), support for some language features, and functions for common tasks such as finding the square root of a number.
It is, however, preferable to use an algorithm from the C++ Standard Library for such tasks. [1] [2] [3] The member function erase can be used to delete an element from a collection, but for containers which are based on an array, such as vector, all elements after the deleted element have to be moved forward to avoid "gaps" in the collection ...
For example, a vector would have a random-access iterator, but a list only a bidirectional iterator. Iterators are the major feature that allow the generality of the STL. For example, an algorithm to reverse a sequence can be implemented using bidirectional iterators, and then the same implementation can be used on lists, vectors and deques.
In modern standard C++, a string literal such as "hello" still denotes a NUL-terminated array of characters. [1] Using C++ classes to implement a string type offers several benefits of automated memory management and a reduced risk of out-of-bounds accesses, [2] and more intuitive syntax for string comparison and concatenation. Therefore, it ...
Similarly, a delete expression calls a delete function, also known as a deallocator function, whose name is operator delete. [ 2 ] [ 3 ] Any new expression that uses the placement syntax is a placement new expression, and any operator new or operator delete function that takes more than the mandatory first parameter ( std :: size_t ) is a ...
Examples include the C++ Standard Template Library std::string, the Qt QString, the MFC CString, and the C-based implementation CFString from Core Foundation as well as its Objective-C sibling NSString from Foundation, both by Apple. More complex structures may also be used to store strings such as the rope.
The C++ standard library instead provides a dynamic array (collection) that can be extended or reduced in its std::vector template class. The C++ standard does not specify any relation between new / delete and the C memory allocation routines, but new and delete are typically implemented as wrappers around malloc and free. [6]