libstdc++-v3/testsuite/20_util/variant/relops/115145.cc

   1 // { dg-do compile { target c++17 } }
   2 // PR libstdc++/115145
   3 // lambda in rewritten std::variant comparisons does not specify return type
   4
   5 #include <variant>
   6
   7 struct Bool {
   8   operator bool() & { return val; }
   9   const bool val;
  10 };
  11
  12 Bool t{true}, f{false};
  13
  14 struct A {
  15   Bool& operator==(const A&) const { return t; }
  16   Bool& operator!=(const A&) const { return f; }
  17   Bool& operator<(const A&) const { return f; }
  18   Bool& operator>(const A&) const { return f; }
  19   Bool& operator<=(const A&) const { return t; }
  20   Bool& operator>=(const A&) const { return t; }
  21 };
  22
  23 bool check_bool(bool);
  24 template<typename T> void check_bool(T) = delete;
  25
  26 void
  27 test_pr115145()
  28 {
  29   std::variant<A> v;
  30   check_bool( v == v );
  31   check_bool( !(v != v) );
  32   check_bool( !(v < v) );
  33   check_bool( !(v > v) );
  34   check_bool( v <= v );
  35   check_bool( v >= v );
  36 }