std::inplace_vector<T,N>::resize

 

C++

Compiler support

Freestanding and hosted

Language

Standard library

Standard library headers

Named requirements

Feature test macros(C++20)

Language support library

Concepts library(C++20)

Diagnostics library

Memory management library

Metaprogramming library(C++11)

General utilities library

Containers library

Iterators library

Ranges library(C++20)

Algorithms library

Strings library

Text processing library

Numerics library

Date and time library

Input/output library

Filesystem library(C++17)

Concurrency support library(C++11)

Execution control library(C++26)

Technical specifications

Symbols index

External libraries

 

Containers library

node-handle (C++17)

Sequence

array (C++11)

vector

vector<bool>

inplace_vector (C++26)

hive (C++26)

deque

forward_list (C++11)

list

Associative

set

multiset

map

multimap

Unordered associative

unordered_set (C++11)

unordered_multiset (C++11)

unordered_map (C++11)

unordered_multimap (C++11)

Adaptors

stack

queue

priority_queue

flat_set (C++23)

flat_multiset (C++23)

flat_map (C++23)

flat_multimap (C++23)

Views

span (C++20)

mdspan (C++23)

Tables

Iterator invalidation

Member function table

Non-member function table

 

std::inplace_vector

Member types
Member functions
inplace_vector::inplace_vector inplace_vector::~inplace_vector    inplace_vector::operator= inplace_vector::assign inplace_vector::assign_range Size and capacity inplace_vector::empty inplace_vector::size inplace_vector::max_size inplace_vector::capacity inplace_vector::resize inplace_vector::reserve inplace_vector::shrink_to_fit Iterators inplace_vector::begininplace_vector::cbegin inplace_vector::endinplace_vector::cend inplace_vector::rbegininplace_vector::crbegin inplace_vector::rendinplace_vector::crend	Element access inplace_vector::at inplace_vector::operator[] inplace_vector::front inplace_vector::back inplace_vector::data Modifiers inplace_vector::clear inplace_vector::erase inplace_vector::swap inplace_vector::insert inplace_vector::insert_range inplace_vector::emplace inplace_vector::emplace_back inplace_vector::try_emplace_back inplace_vector::unchecked_emplace_back inplace_vector::push_back inplace_vector::try_push_back inplace_vector::unchecked_push_back inplace_vector::pop_back inplace_vector::append_range inplace_vector::try_append_range
Non-member functions
erase(std::inplace_vector)erase_if(std::inplace_vector) swap(std::inplace_vector)	operator==operator<=>

 

constexprvoid resize( size_type count );	(1)	(since C++26)
constexprvoid resize( size_type count, const value_type& value );	(2)	(since C++26)

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 default-inserted elements are appended.

2) Additional copies of value are appended.

Parameters

count	-	new size of the container
value	-	the value to initialize the new elements with
Type requirements
- If the following condition is satisfied, the behavior is undefined: 1)T is not DefaultInsertable into inplace_vector. 2)T is not CopyInsertable into inplace_vector.

Complexity

Linear in the difference between the current size and count.

Exceptions

1,2) Throws std::bad_alloc if count > N.

If an exception is thrown for any reason, these functions have no effect (strong exception safety guarantee).

Example

Run this code

#include <inplace_vector>#include <print>   int main(){std::inplace_vector<int, 6> v(6, 9);std::println("Initially, v = {}", v);   v.resize(2);std::println("After resize(2), v = {}", v);   v.resize(4);std::println("After resize(4), v = {}", v);   v.resize(6, -1);std::println("After resize(6, -1), v = {}", v);   try{std::print("Trying resize(13): "); v.resize(13);// throws, because count > N; v is left unchanged}catch(conststd::bad_alloc& ex){std::println("ex.what(): {}", ex.what());}std::println("After exception, v = {}", v);}

Possible output:

Initially, v = [9, 9, 9, 9, 9, 9] After resize(2), v = [9, 9] After resize(4), v = [9, 9, 0, 0] After resize(6, -1), v = [9, 9, 0, 0, -1, -1] Trying resize(13): ex.what(): std::bad_alloc After exception, v = [9, 9, 0, 0, -1, -1]

See also

max_size [static]	returns the maximum possible number of elements (public static member function)
size	returns the number of elements (public member function)
capacity [static]	returns the number of elements that can be held in currently allocated storage (public static member function)
empty	checks whether the container is empty (public member function)