llvm/clang/test/CXX/over/over.oper/over.literal/p2.cpp

// RUN: %clang_cc1 -std=c++11 %s -verify

void operator ""_a(const char *);

namespace N {
  using ::operator ""_a;

  void operator ""_b(const char *);
}

using N::operator ""_b;

class C {
  void operator ""_c(const char *); // expected-error {{must be in a namespace or global scope}}

  static void operator ""_c(unsigned long long); // expected-error {{must be in a namespace or global scope}}

  friend void operator ""_d(const char *);
};

int operator ""_e; // expected-error {{cannot be the name of a variable}}

void f() {
  int operator ""_f; // expected-error {{cannot be the name of a variable}}
}

extern "C++" {
  void operator ""_g(const char *);
}

template<char...> void operator ""_h() {}

template<> void operator ""_h<'a', 'b', 'c'>() {}

template void operator ""_h<'a', 'b', 'c', 'd'>();

namespace rdar13605348 {

class C {
  double operator""_x(long double value) { return double(value); } // expected-error{{literal operator 'operator""_x' must be in a namespace or global scope}}
  double value() { return 3.2_x; } // expected-error{{no matching literal operator for call to}}
};

}