std::list<T,Allocator>::resize - cppreference.com (original) (raw)

Resizes the container to contain count elements:

• If count is equal to the current size, does nothing.
• If the current size is greater than count, the container is reduced to its first count elements.
• If the current size is less than count, then:

1. Additional copies of T()(until C++11)default-inserted elements(since C++11) are appended.

2. Additional copies of value are appended.

[edit] Parameters

[edit] Complexity

Linear in the difference between the current size and count.

Notes

If value-initialization in overload (1) is undesirable, for example, if the elements are of non-class type and zeroing out is not needed, it can be avoided by providing a custom Allocator::construct.

[edit] Example

#include #include   void print(auto rem, const std::list& c) { for (std::cout << rem; const int el : c) std::cout << el << ' '; std::cout << '\n'; }   int main() { std::list c = {1, 2, 3}; print("The list holds: ", c);   c.resize(5); print("After resize up to 5: ", c);   c.resize(2); print("After resize down to 2: ", c);   c.resize(6, 4); print("After resize up to 6 (initializer = 4): ", c); }

Output:

The list holds: 1 2 3 After resize up to 5: 1 2 3 0 0 After resize down to 2: 1 2 After resize up to 6 (initializer = 4): 1 2 4 4 4 4

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

[edit] See also

| | returns the maximum possible number of elements (public member function) [edit] | | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | | returns the number of elements (public member function) [edit] | | | checks whether the container is empty (public member function) [edit] |