std::array (C++11)

In a Nutshell

A fixed-size array that does not decay into a pointer. It offers the performance of a C-style array while supporting standard container interfaces such as size(), iterators, and assignment.

Header

#include <array>

Core API Quick Reference

Operation	Signature	Description
Element access	reference at(size_type pos)	Access element with bounds checking
Element access	reference operator[](size_type pos)	Access element without bounds checking
First element	reference front()	Access the first element
Last element	reference back()	Access the last element
Raw pointer	T* data() noexcept	Direct access to the underlying array pointer
Fill	void fill(const T& value)	Fill all elements with a specified value
Size	constexpr size_type size() noexcept	Returns the number of elements (compile-time constant)
Empty check	constexpr bool empty() noexcept	Checks if the array is empty (true if N==0)
Swap	void swap(array& other)	Swaps the contents of two arrays
Begin iterator	iterator begin() noexcept	Returns an iterator to the beginning

Minimal Example

#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 << ' '; // 输出: 42 0 0
    std::cout << "\nsize: " << arr.size(); // 输出: size: 3
}

Embedded Applicability: High

• Zero-overhead abstraction; compiles to code identical to C-style arrays without introducing heap allocation.
• size() is a compile-time constant, making it suitable for template metaprogramming and static assertions.
• Supports constexpr, ideal for building lookup tables at compile time.
• Built-in bounds checking via at() facilitates debugging, and can be removed in Release builds.

Compiler Support

GCC	Clang	MSVC
4.4	3.1	19.0

See Also

• Tutorial: std::array Deep Dive
• cppreference: std::array

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