std::span::operator[], std::span::operator()

 

C++

Language

Standard Library Headers

Freestanding and hosted implementations

Named requirements

Language support library

Concepts library (C++20)

Diagnostics library

Utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms 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::span

Member functions

span::span

span::operator=

Element access

span::operator[]span::operator()

span::data

Iterators

span::beginspan::cbegin

span::endspan::cend

span::rbeginspan::crbegin

span::rendspan::crend

Observers

span::empty

span::size

span::size_bytes

Subviews

span::first

span::last

span::subspan

Non-member functions

as_bytesas_writable_bytes

Non-member constant

dynamic_extent

Deduction guides

 

constexpr reference operator[](index_type idx) const;
constexpr reference operator()(index_type idx) const;

Returns a reference to the idx-th element of the sequence. The behavior is undefined if idx is out of range (i.e., if it is less than zero or greater than or equal to size()).

Parameters

idx

-

the index of the element to access

Return value

A reference to the idx-th element of the sequence, i.e., data()[idx]

Exceptions

(none)

Notes

operator() is overloaded for consistency with proposed multidimensional arrays, which are indexed as array3D(i, j, k)

See also

data	returns a pointer to the beginning of the sequence of elements (public member function)
size	returns the number of elements in the sequence (public member function)