std::deque<T,Allocator>::insert
From cppreference.com
C++
Feature test macros (C++20)
Concepts library (C++20)
Metaprogramming library (C++11)
Ranges library (C++20)
Filesystem library (C++17)
Concurrency support library (C++11)
Execution control library (C++26)
Containers library
(C++17)
(C++11)
(C++26)
(C++26)
(C++11)
(C++11)
(C++11)
(C++11)
(C++11)
(C++23)
(C++23)
(C++23)
(C++23)
(C++20)
(C++23)
Tables
std::deque
Non-member functions
Deduction guides (C++17)
(C++23)
(C++11)
(C++11)
(C++11)
(C++11)
(DR*)
deque::insert
(C++23)
(C++11)
(C++23)
(C++11)
(C++23)
(until C++20)(until C++20)(until C++20)(until C++20)(until C++20)
iterator insert( const_iterator pos, const T& value );
(1)
(constexpr since C++26)
iterator insert( const_iterator pos, T&& value );
(2)
(since C++11) (constexpr since C++26)
iterator insert( const_iterator pos,
size_type count, const T& value );
(3)
(constexpr since C++26)
size_type count, const T& value );
template< class InputIt >
iterator insert( const_iterator pos, InputIt first, InputIt last );
(4)
(constexpr since C++26)
iterator insert( const_iterator pos, InputIt first, InputIt last );
iterator insert( const_iterator pos, std::initializer_list <T> ilist );
(5)
(since C++11) (constexpr since C++26)
Inserts elements at the specified location in the container.
1) Inserts a copy of value before pos.
If any of the following conditions is satisfied, the behavior is undefined:
-
Tis not CopyInsertable intodeque.
-
Tis not CopyAssignable.
2) Inserts value before pos, possibly using move semantics.
If any of the following conditions is satisfied, the behavior is undefined:
-
Tis not MoveInsertable intodeque. -
Tis not MoveAssignable.
3) Inserts count copies of the value before pos.
If any of the following conditions is satisfied, the behavior is undefined:
-
Tis not CopyInsertable intodeque.
-
Tis not CopyAssignable.
4) Inserts elements from range
[first, last) before pos.
This overload has the same effect as overload (3) if InputIt is an integral type.
This overload participates in overload resolution only if InputIt satisfies the requirements of LegacyInputIterator.
If any of the following conditions is satisfied, the behavior is undefined:
-
Tis not EmplaceConstructible intodequefrom *first. -
Tis not MoveInsertable intodeque. -
Tdoes not satisfy the requirements of MoveConstructible, MoveAssignable or Swappable.
- first or last are iterators into *this.
5) Inserts elements from initializer list ilist before pos.
Equivalent to insert(pos, ilist.begin(), ilist.end()).
All iterators (including the end() iterator) are invalidated. References are invalidated too, unless pos == begin() or pos == end() , in which case they are not invalidated.
Contents
[edit] Parameters
pos
-
iterator before which the content will be inserted
value
-
element value to insert
count
-
number of elements to insert
first, last
-
the pair of iterators defining the range of elements to insert
ilist
-
std::initializer_list to insert the values from
[edit] Return value
1,2) Iterator pointing to the inserted value.
3-5) Iterator pointing to the first element inserted, or pos if no element is inserted.
[edit] Complexity
Linear in the number of elements inserted plus std::min (std::distance (begin(), pos), std::distance (pos, end())).
[edit] Exceptions
If an exception is thrown other than by
- the copy constructor of
T,
- the move constructor of
T,
- the copy assignment operator of
T,
- the move assignment operator of
T,
this function has no effect (strong exception guarantee).
If an exception is thrown when inserting a single element at either end, this function has no effect (strong exception guarantee). Otherwise, if an exception is thrown by the move constructor of a non-CopyInsertable T, the effects are unspecified.
[edit] Example
Run this code
#include <iostream> #include <iterator> #include <string_view> #include <deque> namespace stq { void println(std::string_view rem, const std::deque <int>& container) { std::cout << rem.substr(0, rem.size() - 2) << '['; bool first{true}; for (const int x : container) std::cout << (first ? first = false, "" : ", ") << x; std::cout << "]\n"; } } int main() { std::deque <int> c1(3, 100); stq::println("1. {}", c1); auto pos = c1.begin(); pos = c1.insert(pos, 200); // overload (1) stq::println("2. {}", c1); c1.insert(pos, 2, 300); // overload (3) stq::println("3. {}", c1); // reset pos to the begin: pos = c1.begin(); std::deque <int> c2(2, 400); c1.insert(std::next (pos, 2), c2.begin(), c2.end()); // overload (4) stq::println("4. {}", c1); int arr[] = {501, 502, 503}; c1.insert(c1.begin(), arr, arr + std::size (arr)); // overload (4) stq::println("5. {}", c1); c1.insert(c1.end(), {601, 602, 603}); // overload (5) stq::println("6. {}", c1); }
Output:
1. [100, 100, 100] 2. [200, 100, 100, 100] 3. [300, 300, 200, 100, 100, 100] 4. [300, 300, 400, 400, 200, 100, 100, 100] 5. [501, 502, 503, 300, 300, 400, 400, 200, 100, 100, 100] 6. [501, 502, 503, 300, 300, 400, 400, 200, 100, 100, 100, 601, 602, 603]
[edit] Defect reports
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
| DR | Applied to | Behavior as published | Correct behavior |
|---|---|---|---|
| LWG 149 | C++98 | overloads (3) and (4) returned nothing | returns an iterator |
| LWG 247 | C++98 | the complexity was only specified for inserting a single element |
also specified for inserting multiple elements |