std::array (C++11)

In a Nutshell

A fixed-size array that never decays into a pointer: it delivers the performance of a C-style array while supporting standard container interfaces such as size(), iterators, and assignment.

Header File

#include <array>

Core API Cheat Sheet

Operation	Signature	Description
Element access	`reference at(size_type pos)`	Bounds-checked element access
Element access	`reference operator[](size_type pos)`	Unchecked element access
First element	`reference front()`	Accesses the first element
Last element	`reference back()`	Accesses the last element
Underlying pointer	`T* data() noexcept`	Direct access to the underlying array pointer
Fill	`void fill(const T& value)`	Fills every element with the given value
Size	`constexpr size_type size() noexcept`	Returns the number of elements (a compile-time constant)
Empty check	`constexpr bool empty() noexcept`	Checks whether the array is empty (true when N == 0)
Swap	`void swap(array& other)`	Swaps the contents of two arrays
Begin iterator	`iterator begin() noexcept`	Returns an iterator pointing to the beginning

Minimal Example

C++

#include <array>
#include <iostream>
// Standard: C++11
int main() {
    std::array<int, 3> arr = {1, 2, 3};
    arr.fill(0);
    arr[0] = 42;
    for (const auto& v : arr)
        std::cout << v << ' '; // outputs: 42 0 0
    std::cout << "\nsize: " << arr.size(); // outputs: size: 3
}

Embedded Suitability: High

A zero-overhead abstraction: after compilation it is identical to a C-style array and introduces no heap allocation
size() is a compile-time constant, usable in template metaprogramming and static assertions
Supports constexpr, making it a good fit for building lookup tables at compile time
The built-in bounds check in at() is convenient for debugging and can be removed in Release builds

Compiler Support

GCC	Clang	MSVC
4.4	3.1	19.0

std::array (C++11) ​

In a Nutshell ​

Header File ​

Core API Cheat Sheet ​

Minimal Example ​

Embedded Suitability: High ​

Compiler Support ​

See Also ​