std::vector::push_back

 

C++

Language

Standard library headers

Concepts

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Technical Specifications

 

Containers library

array (C++11)

vector

deque

forward_list (C++11)

list

set

multiset

map

multimap

unordered_set (C++11)

unordered_multiset (C++11)

unordered_map (C++11)

unordered_multimap (C++11)

stack

queue

priority_queue

 

std::vector

Member functions

vector::vector

vector::~vector

vector::operator=

vector::assign

vector::get_allocator

Element access

vector::at

vector::operator[]

vector::front

vector::back

vector::data (C++11)

Iterators

vector::beginvector::cbegin (C++11)

vector::endvector::cend (C++11)

vector::rbeginvector::crbegin (C++11)

vector::rendvector::crend (C++11)

Capacity

vector::empty

vector::size

vector::max_size

vector::reserve

vector::capacity

vector::shrink_to_fit (C++11)

Modifiers

vector::clear

vector::insert

vector::emplace (C++11)

vector::erase

vector::push_back

vector::emplace_back (C++11)

vector::pop_back

vector::resize

vector::swap

 

void push_back( const T& value );	(1)
void push_back( T&& value );	(2)	(since C++11)

Appends the given element value to the end of the container.

1) The new element is initialized as a copy of value.

2) value is moved into the new element.

If the new size() is greater than capacity() then all iterators and references (including the past-the-end iterator) are invalidated. Otherwise only the past-the-end iterator is invalidated.

Parameters

value	-	the value of the element to append
Type requirements
- T must meet the requirements of CopyInsertable in order to use overload (1).
- T must meet the requirements of MoveInsertable in order to use overload (2).

Return value

(none)

Complexity

Amortized constant.

Exceptions

If an exception is thrown, this function has no effect (strong exception guarantee).

If T's move constructor is not noexcept and T is not CopyInsertable into *this, vector will use the throwing move constructor. If it throws, the guarantee is waived and the effects are unspecified.

(since C++11)

Example

Run this code

#include <vector>
#include <iostream>
#include <iomanip>
 
int main()
{
    std::vector<std::string> numbers;
 
    numbers.push_back("abc");
    std::string s = "def";
    numbers.push_back(std::move(s));
 
    std::cout << "vector holds: ";
    for (auto&& i : numbers) std::cout << std::quoted(i) << ' ';
    std::cout << "\nMoved-from string holds " << std::quoted(s) << '\n';
}

Output:

vector holds: "abc" "def" 
Moved-from string holds ""

See also

emplace_back (C++11)	constructs an element in-place at the end (public member function)
pop_back	removes the last element (public member function)