std::span<T,Extent>::begin

 

C++

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span (C++20)

 

std::span

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span::span

span::operator=

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Iterators

span::begin

span::end

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span::empty

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span::size_bytes

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span::first

span::last

span::subspan

Non-member functions

as_bytesas_writable_bytes

Non-member constant

dynamic_extent

Deduction guides

 

constexpr iterator begin() const noexcept;

Returns an iterator to the first element of the span.

If the span is empty, the returned iterator will be equal to end().

Parameters

(none)

Return value

Iterator to the first element.

Complexity

Constant.

Example

Run this code

#include <span>
#include <iostream>
 
void print(std::span<const int> sp)
{
    for(auto it = sp.begin(); it != sp.end(); ++it) {
        std::cout << *it << ' ';
    }
    std::cout << '\n';
}
 
void transmogrify(std::span<int> sp)
{
    if (!sp.empty()) {
        std::cout << *sp.begin() << '\n';
        *sp.begin() = 2;
    }
}
 
int main()
{
    int array[] { 1, 3, 4, 5 };
    print(array);
    transmogrify(array);
    print(array);
}

Output:

1 3 4 5 
1
2 3 4 5

See also

end (C++20)	returns an iterator to the end (public member function)
begincbegin (C++11)(C++14)	returns an iterator to the beginning of a container or array (function template)