1bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant//===----------------------------------------------------------------------===//
2bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant//
3f5256e16dfc425c1d466f6308d4026d529ce9e0bHoward Hinnant//                     The LLVM Compiler Infrastructure
4bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant//
5b64f8b07c104c6cc986570ac8ee0ed16a9f23976Howard Hinnant// This file is dual licensed under the MIT and the University of Illinois Open
6b64f8b07c104c6cc986570ac8ee0ed16a9f23976Howard Hinnant// Source Licenses. See LICENSE.TXT for details.
7bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant//
8bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant//===----------------------------------------------------------------------===//
9bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant
10bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant// <algorithm>
11bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant
12bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant// template<LessThanComparable T>
13bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant//   pair<const T&, const T&>
14bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant//   minmax(const T& a, const T& b);
15bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant
16bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant#include <algorithm>
17bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant#include <cassert>
18bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant
19bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnanttemplate <class T>
20bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnantvoid
21bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnanttest(const T& a, const T& b, const T& x, const T& y)
22bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant{
23bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant    std::pair<const T&, const T&> p = std::minmax(a, b);
24bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant    assert(&p.first == &x);
25bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant    assert(&p.second == &y);
26bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant}
27bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant
28bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnantint main()
29bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant{
30bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant    {
31bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant    int x = 0;
32bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant    int y = 0;
33bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant    test(x, y, x, y);
34bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant    test(y, x, y, x);
35bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant    }
36bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant    {
37bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant    int x = 0;
38bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant    int y = 1;
39bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant    test(x, y, x, y);
40bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant    test(y, x, x, y);
41bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant    }
42bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant    {
43bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant    int x = 1;
44bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant    int y = 0;
45bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant    test(x, y, y, x);
46bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant    test(y, x, y, x);
47bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant    }
489d9463a3555aa559884809b8a7fc842a3968193eMarshall Clow#if _LIBCPP_STD_VER > 11
499d9463a3555aa559884809b8a7fc842a3968193eMarshall Clow    {
509d9463a3555aa559884809b8a7fc842a3968193eMarshall Clow//  Note that you can't take a reference to a local var, since
519d9463a3555aa559884809b8a7fc842a3968193eMarshall Clow//  it's address is not a compile-time constant.
529d9463a3555aa559884809b8a7fc842a3968193eMarshall Clow    constexpr static int x = 1;
539d9463a3555aa559884809b8a7fc842a3968193eMarshall Clow    constexpr static int y = 0;
549d9463a3555aa559884809b8a7fc842a3968193eMarshall Clow    constexpr auto p1 = std::minmax (x, y);
559d9463a3555aa559884809b8a7fc842a3968193eMarshall Clow    static_assert(p1.first  == y, "");
569d9463a3555aa559884809b8a7fc842a3968193eMarshall Clow    static_assert(p1.second == x, "");
579d9463a3555aa559884809b8a7fc842a3968193eMarshall Clow    constexpr auto p2 = std::minmax (y, x);
589d9463a3555aa559884809b8a7fc842a3968193eMarshall Clow    static_assert(p2.first  == y, "");
599d9463a3555aa559884809b8a7fc842a3968193eMarshall Clow    static_assert(p2.second == x, "");
609d9463a3555aa559884809b8a7fc842a3968193eMarshall Clow    }
619d9463a3555aa559884809b8a7fc842a3968193eMarshall Clow#endif
62bc8d3f97eb5c958007f2713238472e0c1c8fe02Howard Hinnant}
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