clang/test/SemaCXX/static-assert-cxx17.cpp

   1 // RUN: %clang_cc1 -fsyntax-only -verify %s -std=c++1z -triple=x86_64-linux-gnu
   2
   3 template <typename U, typename V>
   4 struct S1 {
   5   static constexpr const bool value = false;
   6 };
   7
   8 template <typename U, typename V>
   9 inline constexpr bool global_inline_var = S1<U, V>::value;
  10
  11 template <typename T>
  12 struct S2 {
  13   template <typename U, typename V>
  14   static inline constexpr bool var = global_inline_var<U, V>;
  15 };
  16
  17 template <typename U, typename V>
  18 inline constexpr bool constexpr_return_false() {
  19   return false;
  20 }
  21
  22 template <typename U, typename V>
  23 void foo() {
  24   static_assert(S1<U, V>::value);
  25   // expected-error@-1{{static assertion failed due to requirement 'S1<int, float>::value'}}
  26 }
  27 template void foo<int, float>();
  28 // expected-note@-1{{in instantiation of function template specialization 'foo<int, float>' requested here}}
  29
  30 template <typename U, typename V>
  31 void foo2() {
  32   static_assert(global_inline_var<U, V>);
  33   // expected-error@-1{{static assertion failed due to requirement 'global_inline_var<int, float>'}}
  34 }
  35 template void foo2<int, float>();
  36 // expected-note@-1{{in instantiation of function template specialization 'foo2<int, float>' requested here}}
  37
  38 template <typename T, typename U, typename V>
  39 void foo3() {
  40   static_assert(T::template var<U, V>);
  41   // expected-error@-1{{static assertion failed due to requirement 'S2<long>::var<int, float>'}}
  42 }
  43 template void foo3<S2<long>, int, float>();
  44 // expected-note@-1{{in instantiation of function template specialization 'foo3<S2<long>, int, float>' requested here}}
  45
  46 template <typename T>
  47 void foo4() {
  48   static_assert(S1<T[sizeof(T)], int[4]>::value, "");
  49   // expected-error@-1{{static assertion failed due to requirement 'S1<float[4], int[4]>::value'}}
  50 };
  51 template void foo4<float>();
  52 // expected-note@-1{{in instantiation of function template specialization 'foo4<float>' requested here}}
  53
  54
  55 template <typename U, typename V>
  56 void foo5() {
  57   static_assert(!!(global_inline_var<U, V>));
  58   // expected-error@-1{{static assertion failed due to requirement '!!(global_inline_var<int, float>)'}}
  59 }
  60 template void foo5<int, float>();
  61 // expected-note@-1{{in instantiation of function template specialization 'foo5<int, float>' requested here}}
  62
  63 struct ExampleTypes {
  64   explicit ExampleTypes(int);
  65   using T = int;
  66   using U = float;
  67 };
  68
  69 template <class T>
  70 struct X {
  71   int i = 0;
  72   int j = 0;
  73   constexpr operator bool() const { return false; }
  74 };
  75
  76 template <class T>
  77 void foo6() {
  78   static_assert(X<typename T::T>());
  79   // expected-error@-1{{static assertion failed due to requirement 'X<int>()'}}
  80   static_assert(X<typename T::T>{});
  81   // expected-error@-1{{static assertion failed due to requirement 'X<int>{}'}}
  82   static_assert(X<typename T::T>{1, 2});
  83   // expected-error@-1{{static assertion failed due to requirement 'X<int>{1, 2}'}}
  84   static_assert(X<typename T::T>({1, 2}));
  85   // expected-error@-1{{static assertion failed due to requirement 'X<int>({1, 2})'}}
  86   static_assert(typename T::T{0});
  87   // expected-error@-1{{static assertion failed due to requirement 'int{0}'}}
  88   static_assert(typename T::T(0));
  89   // expected-error@-1{{static assertion failed due to requirement 'int(0)'}}
  90   static_assert(sizeof(X<typename T::T>) == 0);
  91   // expected-error@-1{{static assertion failed due to requirement 'sizeof(X<int>) == 0'}} \
  92   // expected-note@-1 {{evaluates to '8 == 0'}}
  93   static_assert((const X<typename T::T> *)nullptr);
  94   // expected-error@-1{{static assertion failed due to requirement '(const X<int> *)nullptr'}}
  95   static_assert(static_cast<const X<typename T::T> *>(nullptr));
  96   // expected-error@-1{{static assertion failed due to requirement 'static_cast<const X<int> *>(nullptr)'}}
  97   static_assert((const X<typename T::T>[]){} == nullptr);
  98   // expected-error@-1{{static assertion failed due to requirement '(const X<int>[0]){} == nullptr'}}
  99   static_assert(sizeof(X<decltype(X<typename T::T>().X<typename T::T>::~X())>) == 0);
 100   // expected-error@-1{{static assertion failed due to requirement 'sizeof(X<void>) == 0'}} \
 101   // expected-note@-1 {{evaluates to '8 == 0'}}
 102   static_assert(constexpr_return_false<typename T::T, typename T::U>());
 103   // expected-error@-1{{static assertion failed due to requirement 'constexpr_return_false<int, float>()'}}
 104 }
 105 template void foo6<ExampleTypes>();
 106 // expected-note@-1{{in instantiation of function template specialization 'foo6<ExampleTypes>' requested here}}