libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/has_unique_object_representations.pass.cpp

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 // UNSUPPORTED: c++03, c++11, c++14
  10
  11 // type_traits
  12
  13 // has_unique_object_representations
  14
  15 #include <type_traits>
  16
  17 #include "test_macros.h"
  18
  19 template <class T>
  20 void test_has_unique_object_representations()
  21 {
  22     static_assert( std::has_unique_object_representations<T>::value, "");
  23     static_assert( std::has_unique_object_representations<const T>::value, "");
  24     static_assert( std::has_unique_object_representations<volatile T>::value, "");
  25     static_assert( std::has_unique_object_representations<const volatile T>::value, "");
  26
  27     static_assert( std::has_unique_object_representations_v<T>, "");
  28     static_assert( std::has_unique_object_representations_v<const T>, "");
  29     static_assert( std::has_unique_object_representations_v<volatile T>, "");
  30     static_assert( std::has_unique_object_representations_v<const volatile T>, "");
  31 }
  32
  33 template <class T>
  34 void test_has_not_has_unique_object_representations()
  35 {
  36     static_assert(!std::has_unique_object_representations<T>::value, "");
  37     static_assert(!std::has_unique_object_representations<const T>::value, "");
  38     static_assert(!std::has_unique_object_representations<volatile T>::value, "");
  39     static_assert(!std::has_unique_object_representations<const volatile T>::value, "");
  40
  41     static_assert(!std::has_unique_object_representations_v<T>, "");
  42     static_assert(!std::has_unique_object_representations_v<const T>, "");
  43     static_assert(!std::has_unique_object_representations_v<volatile T>, "");
  44     static_assert(!std::has_unique_object_representations_v<const volatile T>, "");
  45 }
  46
  47 class Empty
  48 {
  49 };
  50
  51 class NotEmpty
  52 {
  53     virtual ~NotEmpty();
  54 };
  55
  56 union EmptyUnion {};
  57 struct NonEmptyUnion {int x; unsigned y;};
  58
  59 struct bit_zero
  60 {
  61     int :  0;
  62 };
  63
  64 class Abstract
  65 {
  66     virtual ~Abstract() = 0;
  67 };
  68
  69 struct A
  70 {
  71     ~A();
  72     unsigned foo;
  73 };
  74
  75 struct B
  76 {
  77    char bar;
  78    int foo;
  79 };
  80
  81
  82 int main(int, char**)
  83 {
  84     test_has_not_has_unique_object_representations<void>();
  85     test_has_not_has_unique_object_representations<Empty>();
  86     test_has_not_has_unique_object_representations<EmptyUnion>();
  87     test_has_not_has_unique_object_representations<NotEmpty>();
  88     test_has_not_has_unique_object_representations<bit_zero>();
  89     test_has_not_has_unique_object_representations<Abstract>();
  90     test_has_not_has_unique_object_representations<B>();
  91
  92 //  I would expect all three of these to have unique representations.
  93 //  I would also expect that there are systems where they do not.
  94 //     test_has_not_has_unique_object_representations<int&>();
  95 //     test_has_not_has_unique_object_representations<int *>();
  96 //     test_has_not_has_unique_object_representations<double>();
  97
  98
  99     test_has_unique_object_representations<unsigned>();
 100     test_has_unique_object_representations<NonEmptyUnion>();
 101     test_has_unique_object_representations<char[3]>();
 102     test_has_unique_object_representations<char[]>();
 103
 104
 105   return 0;
 106 }