sortix-mirror/kernel/include/sortix/kernel/yielder.h

66 lines
1.6 KiB
C++

/*
* Copyright (c) 2013 Jonas 'Sortie' Termansen.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* sortix/kernel/yielder.h
* Template that allows creation of easily-iterable sequences.
*/
#ifndef _INCLUDE_SORTIX_KERNEL_YIELDER_H
#define _INCLUDE_SORTIX_KERNEL_YIELDER_H
namespace Sortix {
class finished_yielder { };
template <class yielder_type, class yielded_type> class yielder_iterator
{
public:
yielder_iterator(yielder_type yielder) : yielder_object(yielder)
{
has_value = yielder_object.yield(&current_value);
}
bool is_finished() const
{
return !has_value;
}
bool operator!=(const yielder_iterator& other) const
{
return !(is_finished() && other.is_finished());
}
yielded_type operator*()
{
return current_value;
}
const yielder_iterator& operator++()
{
has_value = yielder_object.yield(&current_value);
return *this;
}
private:
yielder_type yielder_object;
yielded_type current_value;
bool has_value;
};
} // namespace Sortix
#endif