Difference between revisions of "Template:cpp/container/push back"
From cppreference.com
m (fmt) |
m (+reallocation note for vector, there are still some duplications on vector page, WIP) |
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@1@ The new element is initialized as a copy of {{c|value}}. | @1@ The new element is initialized as a copy of {{c|value}}. | ||
| − | |||
@2@ {{c|value}} is moved into the new element. | @2@ {{c|value}} is moved into the new element. | ||
| − | {{cpp/container/ | + | {{cpp/container/vector/reallocation note|{{{1|}}}}} |
| + | {{cpp/container/note iterator invalidation|{{{1|}}}|push_back}} | ||
===Parameters=== | ===Parameters=== | ||
| Line 55: | Line 55: | ||
{{#ifeq:{{{1|}}}|vector| | {{#ifeq:{{{1|}}}|vector| | ||
{{rrev|since=c++11| | {{rrev|since=c++11| | ||
| − | If {{tt|T}}'s move constructor is not {{c|noexcept}} and T is not {{named req|CopyInsertable}} into {{c|*this}}, vector will use the throwing move constructor. If it throws, the guarantee is waived and the effects are unspecified. | + | If {{tt|T}}'s move constructor is not {{c|noexcept}} and {{tt|T}} is not {{named req|CopyInsertable}} into {{c|*this}}, vector will use the throwing move constructor. If it throws, the guarantee is waived and the effects are unspecified. |
}} | }} | ||
<!----> | <!----> | ||
===Notes=== | ===Notes=== | ||
| − | + | Some implementations throw {{lc|std::length_error}} when {{tt|push_back}} causes a reallocation that exceeds {{lc|max_size}} (due to an implicit call to an equivalent of {{lc|reserve}}{{tt|(}}{{lc|size}}{{tt|() + 1))}}. | |
}} | }} | ||
<!----> | <!----> | ||
Revision as of 06:11, 10 August 2023
| void push_back( const T& value ); |
(1) | (since {std}) |
| 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.
| Information on iterator invalidation is copied from here |
Contents |
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
| Templated information. See page source. |
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).
Example
Run this code
#include <iomanip> #include <iostream> #include <string> #include <list> int main() { std::list<std::string> letters; letters.push_back("abc"); std::string s{"def"}; letters.push_back(std::move(s)); std::cout << "std::list letters holds: "; for (auto&& e : letters) std::cout << std::quoted(e) << ' '; std::cout << "\nMoved-from string s holds: " << std::quoted(s) << '\n'; }
Possible output:
std::list letters holds: "abc" "def" Moved-from string s holds: ""
See also
| (C++11) |
constructs an element in-place at the end (public member function of std::{{{1}}})
|
| inserts an element to the beginning (public member function of std::{{{1}}})
| |
| removes the last element (public member function of std::{{{1}}})
| |
| creates a std::back_insert_iterator of type inferred from the argument (function template) |
