vector Class

Article
01/12/2013

The STL vector class is a template class of sequence containers that arrange elements of a given type in a linear arrangement and allow fast random access to any element. They should be the preferred container for a sequence when random-access performance is at a premium.

template < 
   class Type,  
   class Allocator = allocator<Type>  
> 
class vector

Parameters

Type
The element data type to be stored in the vector
Allocator
The type that represents the stored allocator object that encapsulates details about the vector's allocation and deallocation of memory. This argument is optional and the default value is allocator*<Type>.*

Remarks

Vectors allow constant time insertions and deletions at the end of the sequence. Inserting or deleting elements in the middle of a vector requires linear time. The performance of the deque Class container is superior with respect to insertions and deletions at the beginning and end of a sequence. The list Class container is superior with respect to insertions and deletions at any location within a sequence.

Vector reallocation occurs when a member function must increase the sequence contained in the vector object beyond its current storage capacity. Other insertions and erasures may alter various storage addresses within the sequence. In all such cases, iterators or references that point at altered portions of the sequence become invalid. If no reallocation happens, only iterators and references before the insertion/deletion point remain valid.

The vector<bool> Class is a full specialization of the template class vector for elements of type bool with an allocator for the underlying type used by the specialization.

The vector<bool> reference Class is a nested class whose objects are able to provide references to elements (single bits) within a vector<bool> object.

Members

Constructors

vector

Constructs a vector of a specific size or with elements of a specific value or with a specific allocator or as a copy of some other vector.

Typedefs

allocator_type	A type that represents the allocator class for the vector object.
const_iterator	A type that provides a random-access iterator that can read a const element in a vector.
const_pointer	A type that provides a pointer to a const element in a vector.
const_reference	A type that provides a reference to a const element stored in a vector for reading and performing const operations.
const_reverse_iterator	A type that provides a random-access iterator that can read any const element in the vector.
difference_type	A type that provides the difference between the addresses of two elements in a vector.
iterator	A type that provides a random-access iterator that can read or modify any element in a vector.
pointer	A type that provides a pointer to an element in a vector.
reference	A type that provides a reference to an element stored in a vector.
reverse_iterator	A type that provides a random-access iterator that can read or modify any element in a reversed vector.
size_type	A type that counts the number of elements in a vector.
value_type	A type that represents the data type stored in a vector.

Member Functions

assign	Erases a vector and copies the specified elements to the empty vector.
at	Returns a reference to the element at a specified location in the vector.
back	Returns a reference to the last element of the vector.
begin	Returns a random-access iterator to the first element in the vector.
capacity	Returns the number of elements that the vector could contain without allocating more storage.
cbegin	Returns a random-access const iterator to the first element in the vector.
cend	Returns a random-access const iterator that points just beyond the end of the vector.
crbegin	Returns a const iterator to the first element in a reversed vector.
crend	Returns a const iterator to the end of a reversed vector.
clear	Erases the elements of the vector.
data	Returns a pointer to the first element in the vector.
emplace	Inserts an element constructed in place into the vector at a specified position.
emplace_back	Adds an element constructed in place to the end of the vector.
empty	Tests if the vector container is empty.
end	Returns a random-access iterator that points to the end of the vector.
erase	Removes an element or a range of elements in a vector from specified positions.
front	Returns a reference to the first element in a vector.
get_allocator	Returns an object to the allocator class used by a vector.
insert	Inserts an element or a number of elements into the vector at a specified position.
max_size	Returns the maximum length of the vector.
pop_back	Deletes the element at the end of the vector.
push_back	Add an element to the end of the vector.
rbegin	Returns an iterator to the first element in a reversed vector.
rend	Returns an iterator to the end of a reversed vector.
reserve	Reserves a minimum length of storage for a vector object.
resize	Specifies a new size for a vector.
shrink_to_fit	Discards excess capacity.
size	Returns the number of elements in the vector.
swap	Exchanges the elements of two vectors.

Operators

operator[]	Returns a reference to the vector element at a specified position.
operator=	Replaces the elements of the vector with a copy of another vector.

Requirements

Header: <vector>

Namespace: std

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vector Class

Parameters

Remarks

Members

Constructors

Typedefs

Member Functions

Operators

Requirements

See Also

Reference

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