std::begin, std::cbegin

Since C++14

Header: <array>

Returns an iterator to the beginning of the given range.

# Declarations

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

(since C++11) (constexpr since C++17)

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

(since C++11) (constexpr since C++17)

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

(since C++11) (noexcept since C++14) (constexpr since C++14)

template< class C >
constexpr auto cbegin( const C& c ) noexcept(/* see below */)
-> decltype(std::begin(c));

(since C++14)

# Parameters

c: a container or view with a begin member function
array: an array of arbitrary type

# Notes

The non-array overloads exactly reflect the behavior of C::begin. Their effects may be surprising if the member function does not have a reasonable implementation.

std::cbegin is introduced for unification of member and non-member range accesses. See also LWG issue 2128.

If C is a shallow-const view, std::cbegin may return a mutable iterator. Such behavior is unexpected for some users. See also P2276 and P2278.

# Example

#include <iostream>
#include <iterator>
#include <vector>
 
int main() 
{
    std::vector<int> v = {3, 1, 4};
    auto vi = std::begin(v);
    std::cout << std::showpos << *vi << '\n'; 
 
    int a[] = {-5, 10, 15};
    auto ai = std::begin(a);
    std::cout << *ai << '\n';
}