File: libstdcxx_libcxx_less_hack.cpp

package info (click to toggle)
llvm-toolchain-11 1%3A11.0.1-2
  • links: PTS, VCS
  • area: main
  • in suites: bullseye
  • size: 995,808 kB
  • sloc: cpp: 4,767,656; ansic: 760,916; asm: 477,436; python: 170,940; objc: 69,804; lisp: 29,914; sh: 23,855; f90: 18,173; pascal: 7,551; perl: 7,471; ml: 5,603; awk: 3,489; makefile: 2,573; xml: 915; cs: 573; fortran: 503; javascript: 452
file content (67 lines) | stat: -rw-r--r-- 1,918 bytes parent folder | download | duplicates (31)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
// This is a test for a hack in Clang that works around a problem introduced by
// DR583: it's no longer possible to compare a pointer against nullptr_t, but
// we still want to permit those comparisons within less<> and friends.

// RUN: %clang_cc1 -verify %s -std=c++14

namespace std {
  template<typename T = void> struct less {};
  template<typename T = void> struct less_equal {};
  template<typename T = void> struct greater {};
  template<typename T = void> struct greater_equal {};

  template<> struct less<> {
    template <class T1, class T2>
    auto operator()(T1 &&t, T2 &&u) const noexcept(noexcept(t < u))
        -> decltype(t < u) {
      return t < u;
    }
  };

  template<> struct less_equal<> {
    template <class T1, class T2>
    auto operator()(T1 &&t, T2 &&u) const noexcept(noexcept(t <= u))
        -> decltype(t <= u) {
      return t <= u;
    }
  };

  template<> struct greater<> {
    template <class T1, class T2>
    auto operator()(T1 &&t, T2 &&u) const noexcept(noexcept(t > u))
        -> decltype(t > u) {
      return t > u;
    }
  };

  template<> struct greater_equal<> {
    template <class T1, class T2>
    auto operator()(T1 &&t, T2 &&u) const noexcept(noexcept(t >= u))
        -> decltype(t >= u) {
      return t >= u;
    }
  };

  template<typename = void> struct unrelated;
  template<> struct unrelated<> {
    template <class T1, class T2>
    auto operator()(T1 &&t, T2 &&u) const noexcept(noexcept(t < u)) // expected-note {{substitution failure}}
        -> decltype(t < u) {
      return t < u;
    }
  };
};

void test(int *p) {
  using namespace std;
  less<>()(p, nullptr);
  less<>()(nullptr, p);
  less_equal<>()(p, nullptr);
  less_equal<>()(nullptr, p);
  greater<>()(p, nullptr);
  greater<>()(nullptr, p);
  greater_equal<>()(p, nullptr);
  greater_equal<>()(nullptr, p);

  unrelated<>()(p, nullptr); // expected-error {{no matching function}}
}