std::vector::clear

C++

Language

Headers

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Named requirements

Language support library

Concepts library (C++20)

Diagnostics library

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Filesystem library (C++17)

Technical Specifications

Containers library

array (C++11)

vector

deque

forward_list (C++11)

list

set

multiset

map

multimap

unordered_set (C++11)

unordered_multiset (C++11)

unordered_map (C++11)

unordered_multimap (C++11)

stack

queue

priority_queue

span (C++20)

std::vector

Member functions

vector::vector

vector::~vector

vector::operator=

vector::assign

vector::get_allocator

Element access

vector::at

vector::operator[]

vector::front

vector::back

vector::data (C++11)

Iterators

vector::beginvector::cbegin (C++11)

vector::endvector::cend (C++11)

vector::rbeginvector::crbegin (C++11)

vector::rendvector::crend (C++11)

Capacity

vector::empty

vector::size

vector::max_size

vector::reserve

vector::capacity

vector::shrink_to_fit (C++11)

Modifiers

vector::clear

vector::insert

vector::emplace (C++11)

vector::erase

vector::push_back

vector::emplace_back (C++11)

vector::pop_back

vector::resize

vector::swap

Deduction guides(C++17)

void clear();		(until C++11)
void clear() noexcept;		(since C++11)

Removes 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 iterators are also invalidated.

Leaves the capacity() of the vector unchanged (note: the standard's restriction on the changes to capacity is in the specification of vector::reserve, see [1])

Parameters

(none)

Return value

(none)

Complexity

Linear in the size of the container, i.e., the number of elements.

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 omitted in C++11	complexity reaffirmed as linear

See also

erase

erases elements (public member function)