1//////////////////////////////////////////////////////////////////////////////
2//
3// (C) Copyright Ion Gaztanaga 2015-2016.
4// Distributed under the Boost Software License, Version 1.0.
5// (See accompanying file LICENSE_1_0.txt or copy at
6// http://www.boost.org/LICENSE_1_0.txt)
7//
8// See http://www.boost.org/libs/move for documentation.
9//
10//////////////////////////////////////////////////////////////////////////////
11
12#ifndef BOOST_MOVE_ADAPTIVE_MERGE_HPP
13#define BOOST_MOVE_ADAPTIVE_MERGE_HPP
14
15#include <boost/move/detail/config_begin.hpp>
16#include <boost/move/algo/detail/adaptive_sort_merge.hpp>
17
18namespace boost {
19namespace movelib {
20
21//! <b>Effects</b>: Merges two consecutive sorted ranges [first, middle) and [middle, last)
22//! into one sorted range [first, last) according to the given comparison function comp.
23//! The algorithm is stable (if there are equivalent elements in the original two ranges,
24//! the elements from the first range (preserving their original order) precede the elements
25//! from the second range (preserving their original order).
26//!
27//! <b>Requires</b>:
28//! - RandIt must meet the requirements of ValueSwappable and RandomAccessIterator.
29//! - The type of dereferenced RandIt must meet the requirements of MoveAssignable and MoveConstructible.
30//!
31//! <b>Parameters</b>:
32//! - first: the beginning of the first sorted range.
33//! - middle: the end of the first sorted range and the beginning of the second
34//! - last: the end of the second sorted range
35//! - comp: comparison function object which returns true if the first argument is is ordered before the second.
36//! - uninitialized, uninitialized_len: raw storage starting on "uninitialized", able to hold "uninitialized_len"
37//! elements of type iterator_traits<RandIt>::value_type. Maximum performance is achieved when uninitialized_len
38//! is min(std::distance(first, middle), std::distance(middle, last)).
39//!
40//! <b>Throws</b>: If comp throws or the move constructor, move assignment or swap of the type
41//! of dereferenced RandIt throws.
42//!
43//! <b>Complexity</b>: Always K x O(N) comparisons and move assignments/constructors/swaps.
44//! Constant factor for comparisons and data movement is minimized when uninitialized_len
45//! is min(std::distance(first, middle), std::distance(middle, last)).
46//! Pretty good enough performance is achieved when uninitialized_len is
47//! ceil(sqrt(std::distance(first, last)))*2.
48//!
49//! <b>Caution</b>: Experimental implementation, not production-ready.
50template<class RandIt, class Compare>
51void adaptive_merge( RandIt first, RandIt middle, RandIt last, Compare comp
52 , typename iterator_traits<RandIt>::value_type* uninitialized = 0
53 , std::size_t uninitialized_len = 0)
54{
55 typedef typename iterator_traits<RandIt>::size_type size_type;
56 typedef typename iterator_traits<RandIt>::value_type value_type;
57
58 ::boost::movelib::detail_adaptive::adaptive_xbuf<value_type> xbuf(uninitialized, uninitialized_len);
59 ::boost::movelib::detail_adaptive::adaptive_merge_impl(first, size_type(middle - first), size_type(last - middle), comp, xbuf);
60}
61
62} //namespace movelib {
63} //namespace boost {
64
65#include <boost/move/detail/config_end.hpp>
66
67#endif //#define BOOST_MOVE_ADAPTIVE_MERGE_HPP
68