eonix/gblibstdc++/include/bits/iter_ops

#ifndef __GBLIBCPP_BITS_ITER_OPS__
#define __GBLIBCPP_BITS_ITER_OPS__

namespace std {

template <typename Container>
constexpr auto begin(Container& c) -> decltype(c.begin())
{ return c.begin(); }

template <typename Container>
constexpr auto begin(const Container& c) -> decltype(c.begin())
{ return c.begin(); }

template <typename Container>
constexpr auto end(Container& c) -> decltype(c.end())
{ return c.end(); }

template <typename Container>
constexpr auto end(const Container& c) -> decltype(c.end())
{ return c.end(); }

template <typename Container>
constexpr auto cbegin(const Container& c)
    noexcept(noexcept(std::begin(c))) -> decltype(c.begin())
{ return c.begin(); }

template <typename Container>
constexpr auto cend(const Container& c)
    noexcept(noexcept(std::end(c))) -> decltype(c.end())
{ return c.end(); }

} // namespace std

#endif