clang/test/SemaCXX/std-compare-cxx2a.cpp

   1 // Test diagnostics for ill-formed STL <compare> headers.
   2
   3 // RUN: %clang_cc1 -triple x86_64-apple-darwin -fcxx-exceptions -fsyntax-only -pedantic -verify -Wsign-compare -std=c++2a %s
   4 // RUN: %clang_cc1 -triple x86_64-apple-darwin -fcxx-exceptions -fsyntax-only -pedantic -verify -Wsign-compare -std=c++2a -DTEST_TRIVIAL=1 %s
   5
   6 #ifndef TEST_TRIVIAL
   7 void compare_not_found_test() {
   8   // expected-error@+1 {{cannot use builtin operator '<=>' because type 'std::partial_ordering' was not found; include <compare>}}
   9   (void)(0.0 <=> 42.123);
  10 }
  11
  12 struct deduction_compare_not_found {
  13   // expected-error@+1 {{cannot default 'operator<=>' because type 'std::strong_ordering' was not found; include <compare>}}
  14   friend auto operator<=>(const deduction_compare_not_found&, const deduction_compare_not_found&) = default;
  15 };
  16
  17 struct comparable {
  18   int operator<=>(comparable);
  19 };
  20 struct default_compare_not_found {
  21   // expected-error@+1 {{cannot default 'operator<=>' because type 'std::strong_ordering' was not found; include <compare>}}
  22   friend int operator<=>(const default_compare_not_found&, const default_compare_not_found&) = default;
  23 };
  24 bool b = default_compare_not_found() < default_compare_not_found(); // expected-note {{first required here}}
  25
  26 namespace std {
  27 inline namespace __1 {
  28 struct partial_ordering; // expected-note {{forward declaration}}
  29 }
  30 } // namespace std
  31
  32 auto compare_incomplete_test() {
  33   // expected-error@+1 {{incomplete type 'std::partial_ordering' where a complete type is required}}
  34   return (-1.2 <=> 123.0);
  35 }
  36
  37 namespace std {
  38 inline namespace __1 {
  39 struct partial_ordering {
  40   unsigned value;
  41 };
  42 } // namespace __1
  43 } // namespace std
  44
  45 auto missing_member_test() {
  46   // expected-error@+1 {{standard library implementation of 'std::partial_ordering' is not supported; member 'equivalent' is missing}}
  47   return (1.0 <=> 1.0);
  48 }
  49
  50 namespace std {
  51 inline namespace __1 {
  52 struct strong_ordering {
  53   long long value;
  54   static const strong_ordering equal; // expected-note {{declared here}}
  55 };
  56 } // namespace __1
  57 } // namespace std
  58
  59 auto test_non_constexpr_var() {
  60   // expected-error@+1 {{standard library implementation of 'std::strong_ordering' is not supported; member 'equal' does not have expected form}}
  61   return (1 <=> 0);
  62 }
  63
  64 #else
  65
  66 namespace std {
  67 inline namespace __1 {
  68 struct strong_ordering {
  69   char value = 0;
  70   constexpr strong_ordering() = default;
  71   // non-trivial
  72   constexpr strong_ordering(strong_ordering const &other) : value(other.value) {}
  73 };
  74 } // namespace __1
  75 } // namespace std
  76
  77 auto test_non_trivial(int LHS, int RHS) {
  78   // expected-error@+1 {{standard library implementation of 'std::strong_ordering' is not supported; the type is not trivially copyable}}
  79   return LHS <=> RHS;
  80 }
  81
  82 #endif