std::list<T,Allocator>::assign
From cppreference.com
void assign( size_type count, const T& value ); |
(1) | |
template< class InputIt > void assign( InputIt first, InputIt last ); |
(2) | |
void assign( std::initializer_list<T> ilist ); |
(3) | (since C++11) |
Replaces the contents of the container.
1) Replaces the contents with count copies of value value.
2) Replaces the contents with copies of those in the range
[
first,
last)
. The behavior is undefined if either argument is an iterator into *this.
This overload has the same effect as overload (1) if |
(until C++11) |
This overload participates in overload resolution only if |
(since C++11) |
3) Replaces the contents with the elements from the initializer list ilist.
All iterators, pointers and references to the elements of the container are invalidated.
Contents |
[edit] Parameters
count | - | the new size of the container |
value | - | the value to initialize elements of the container with |
first, last | - | the range to copy the elements from |
ilist | - | initializer list to copy the values from |
[edit] Complexity
1) Linear in count.
2) Linear in distance between first and last.
3) Linear in ilist.size().
[edit] Example
The following code uses assign
to add several characters to a std::list<char>:
Run this code
#include <list> #include <iostream> #include <string> int main() { std::list<char> characters; auto print_list = [&]() { for (char c : characters) std::cout << c << ' '; std::cout << '\n'; }; characters.assign(5, 'a'); print_list(); const std::string extra(6, 'b'); characters.assign(extra.begin(), extra.end()); print_list(); characters.assign({'C', '+', '+', '1', '1'}); print_list(); }
Output:
a a a a a b b b b b b C + + 1 1
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 320 | C++98 | the replacement operation was defined as erasing all existing elements followed by inserting the given elements |
removed the definition |
[edit] See also
(C++23) |
assigns a range of values to the container (public member function) |
assigns values to the container (public member function) |