std::data

Defined in header <iterator>

Defined in header <array>

Defined in header <deque>

Defined in header <forward_list>

Defined in header <list>

Defined in header <map>

Defined in header <regex>

Defined in header <set>

Defined in header <string>

Defined in header <unordered_map>

Defined in header <unordered_set>

Defined in header <vector>

template <class C> 
constexpr auto data(C& c) -> decltype(c.data());

(1)

(since C++17)

template <class C> 
constexpr auto data(const C& c) -> decltype(c.data());

(2)

(since C++17)

template <class T, std::size_t N> 
constexpr T* data(T (&array)[N]) noexcept;

(3)

(since C++17)

template <class E>
constexpr const E* data(std::initializer_list<E> il) noexcept;

(4)

(since C++17)

Returns a pointer to the block of memory containing the elements of the container.

1,2) returns c.data()

3) returns array

4) returns il.begin()

c	-	a container with a `data()` method
array	-	an array of arbitrary type
il	-	an initializer list

A pointer to the block of memory containing the elements of the container.

3,4)

noexcept specification:

noexcept

First version

template <class C> 
constexpr auto data(C& c) -> decltype(c.data())
{
    return c.data();
}

Second version

template <class C> 
constexpr auto data(const C& c) -> decltype(c.data())
{
    return c.data();
}

Third version

template <class T, std::size_t N>
constexpr T* data(T (&array)[N]) noexcept
{
    return array;
}

Fourth version

template <class E> 
constexpr const E* data(std::initializer_list<E> il) noexcept
{
    return il.begin();
}

Links:

doc_CPP

2025-01-10 15:47:30

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