table of contents
std::list::clear(3) | C++ Standard Libary | std::list::clear(3) |
NAME¶
std::list::clear - std::list::clear
Synopsis¶
void clear(); (until C++11)
void clear() noexcept; (since C++11)
Erases all elements from the container. After this call, size() returns
zero.
Invalidates any references, pointers, or iterators referring to contained
elements.
Any past-the-end iterator remains valid.
Parameters¶
(none)
Return value¶
(none)
Complexity¶
Linear in the size of the container, i.e., the number of elements.
Example¶
// Run this code
#include <algorithm>
#include <iostream>
#include <list>
int main()
{
std::list<int> container{1, 2, 3};
auto print = [](const int& n) { std::cout << " " <<
n; };
std::cout << "Before clear:";
std::for_each(container.begin(), container.end(), print);
std::cout << "\nSize=" << container.size() <<
'\n';
std::cout << "Clear\n";
container.clear();
std::cout << "After clear:";
std::for_each(container.begin(), container.end(), print);
std::cout << "\nSize=" << container.size() <<
'\n';
}
Output:¶
Before clear: 1 2 3
Size=3
Clear
After clear:
Size=0
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 2231 C++11 complexity guarantee was mistakenly complexity reaffirmed as
omitted in C++11 linear
See also¶
erase erases elements
(public member function)
2022.07.31 | http://cppreference.com |