| 1 | // This is a test for a hack in Clang that works around a problem introduced by |
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| 2 | // DR583: it's no longer possible to compare a pointer against nullptr_t, but |
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| 3 | // we still want to permit those comparisons within less<> and friends. |
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| 4 | |
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| 5 | // RUN: %clang_cc1 -verify %s -std=c++14 |
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| 6 | |
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| 7 | namespace std { |
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| 8 | template<typename T = void> struct less {}; |
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| 9 | template<typename T = void> struct less_equal {}; |
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| 10 | template<typename T = void> struct greater {}; |
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| 11 | template<typename T = void> struct greater_equal {}; |
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| 12 | |
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| 13 | template<> struct less<> { |
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| 14 | template <class T1, class T2> |
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| 15 | auto operator()(T1 &&t, T2 &&u) const noexcept(noexcept(t < u)) |
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| 16 | -> decltype(t < u) { |
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| 17 | return t < u; |
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| 18 | } |
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| 19 | }; |
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| 20 | |
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| 21 | template<> struct less_equal<> { |
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| 22 | template <class T1, class T2> |
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| 23 | auto operator()(T1 &&t, T2 &&u) const noexcept(noexcept(t <= u)) |
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| 24 | -> decltype(t <= u) { |
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| 25 | return t <= u; |
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| 26 | } |
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| 27 | }; |
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| 28 | |
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| 29 | template<> struct greater<> { |
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| 30 | template <class T1, class T2> |
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| 31 | auto operator()(T1 &&t, T2 &&u) const noexcept(noexcept(t > u)) |
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| 32 | -> decltype(t > u) { |
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| 33 | return t > u; |
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| 34 | } |
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| 35 | }; |
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| 36 | |
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| 37 | template<> struct greater_equal<> { |
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| 38 | template <class T1, class T2> |
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| 39 | auto operator()(T1 &&t, T2 &&u) const noexcept(noexcept(t >= u)) |
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| 40 | -> decltype(t >= u) { |
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| 41 | return t >= u; |
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| 42 | } |
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| 43 | }; |
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| 44 | |
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| 45 | template<typename = void> struct unrelated; |
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| 46 | template<> struct unrelated<> { |
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| 47 | template <class T1, class T2> |
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| 48 | auto operator()(T1 &&t, T2 &&u) const noexcept(noexcept(t < u)) // expected-note {{substitution failure}} |
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| 49 | -> decltype(t < u) { |
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| 50 | return t < u; |
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| 51 | } |
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| 52 | }; |
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| 53 | }; |
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| 54 | |
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| 55 | void test(int *p) { |
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| 56 | using namespace std; |
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| 57 | less<>()(p, nullptr); |
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| 58 | less<>()(nullptr, p); |
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| 59 | less_equal<>()(p, nullptr); |
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| 60 | less_equal<>()(nullptr, p); |
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| 61 | greater<>()(p, nullptr); |
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| 62 | greater<>()(nullptr, p); |
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| 63 | greater_equal<>()(p, nullptr); |
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| 64 | greater_equal<>()(nullptr, p); |
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| 65 | |
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| 66 | unrelated<>()(p, nullptr); // expected-error {{no matching function}} |
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| 67 | } |
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| 68 | |
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