std::vector::reserve

From cppreference.com

void reserve( size_type size );

Sets the capacity of the container to at least size. New storage is allocated if necessary.

If size() is greater than capacity(), all iterators and references, including the past-the-end iterator, are invalidated. Otherwise, no iterators or references are invalidated.

Contents

[edit] Parameters

size - new capacity of the container

[edit] Return value

(none)

[edit] Exceptions

std::length_error if size > max_size().

[edit] Complexity

Linear in the size of the container

[edit] See also

returns the number of elements that can be held in currently allocated storage
(public member function)