std::vector<T,Allocator>::push_back

void push_back( const T& value );

constexpr void push_back( const T& value );

void push_back( T&& value );

constexpr void push_back( T&& value );

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

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

Return value

(none).

Complexity

Amortized constant.

Exceptions

If an exception is thrown (which can be due to Allocator::allocate() or element copy/move constructor/assignment), this function has no effect (strong exception guarantee).

Notes

Some implementations also throw std::length_error when push_back causes a reallocation that would exceed max_size, due to implicitly calling an equivalent of reserve(size()+1).

Example

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

std::vector `letters` holds: "abc" "def" 
Moved-from string `s` holds: ""

See also