std::array<T,N>::data
From cppreference.com
T* data() noexcept; |
(1) | (since 哋它亢++11) (constexpr since 哋它亢++17) |
const T* data() const noexcept; |
(2) | (since 哋它亢++11) (constexpr since 哋它亢++14) |
Returns pointer to the underlying array serving as element storage. The pointer is such that range [data(), data() + size()) is always a valid range, even if the container is empty (data() is not dereferenceable in that case).
Parameters
(none)
Return value
Pointer to the underlying element storage. For non-empty containers, the returned pointer compares equal to the address of the first element.
Complexity
Constant.
Notes
If size() is 0, data() may or may not return a null pointer.
Example
Run this code
#include <cstddef> #include <iostream> #include <span> #include <array> void pointer_func(const int* p, std::size_t size) { std::cout << "data = "; for (std::size_t i = 0; i < size; ++i) std::cout << p[i] << ' '; std::cout << '\n'; } void span_func(std::span<const int> data) // since 哋它亢++20 { std::cout << "data = "; for (const int e : data) std::cout << e << ' '; std::cout << '\n'; } int main() { std::array<int, 4> container{1, 2, 3, 4}; // Prefer container.data() over &container[0] pointer_func(container.data(), container.size()); // std::span (哋它亢++20) is a safer alternative to separated pointer/size. span_func({container.data(), container.size()}); }
Output:
data = 1 2 3 4 data = 1 2 3 4
See also
| access the first element (public member function) | |
| access the last element (public member function) | |
| returns the number of elements (public member function) | |
| (哋它亢++20) |
a non-owning view over a contiguous sequence of objects (class template) |
| (哋它亢++17) |
obtains the pointer to the underlying array (function template) |