begin.hpp

Go to the documentation of this file.

// SPDX-License-Identifier: BSL-1.0
// SPDX-FileCopyrightText: Copyright (C) 2019 Tobias Hienzsch
 
#ifndef TETL_ITERATOR_BEGIN_HPP
#define TETL_ITERATOR_BEGIN_HPP
 
#include <etl/_cstddef/size_t.hpp>
 
namespace etl {
 
/// \brief Returns an iterator to the beginning of the given container c or
/// array array. These templates rely on `C::begin()` having a reasonable
/// implementation. Returns exactly c.begin(), which is typically an iterator to
/// the beginning of the sequence represented by c. If C is a standard
/// Container, this returns `C::iterator` when c is not const-qualified, and
/// `C::const_iterator` otherwise. Custom overloads of begin may be provided for
/// classes that do not expose a suitable begin() member function, yet can be
/// iterated.
/// \ingroup iterator
template <typename C>
constexpr auto begin(C& c) -> decltype(c.begin())
{
    return c.begin();
}
 
/// \ingroup iterator
template <typename C>
constexpr auto begin(C const& c) -> decltype(c.begin())
{
    return c.begin();
}
 
/// \ingroup iterator
template <typename T, etl::size_t N>
constexpr auto begin(T (&array)[N]) noexcept -> T*
{
    return &array[0];
}
 
/// \ingroup iterator
template <typename C>
constexpr auto cbegin(C const& c) noexcept(noexcept(begin(c))) -> decltype(begin(c))
{
    return begin(c);
}
 
} // namespace etl
 
#endif // TETL_ITERATOR_BEGIN_HPP