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

Returns an iterator to the beginning of the given range.

[ edit ] Exceptions

[ edit ] Overloads

Custom overloads of begin may be provided for classes and enumerations that do not expose a suitable begin() member function, yet can be iterated. The following overloads are already provided by the standard library:

[ edit ] 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 .

[ edit ] 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';
Output:
[edit] See also

template<typename Container, typename Function>
void for_each(Container&& cont, Function f)
    using std::begin;
    auto it = begin(cont);
    using std::end;
    auto end_it = end(cont);
    while (it != end_it)
        f(*it);
        ++it;
Overloads of begin found by argument-dependent lookup can be used to customize the behavior of std::ranges::begin, std::ranges::cbegin, and other customization pointer objects depending on std::ranges::begin.