clang/test/CXX/expr/expr.post/expr.const.cast/p1-0x.cpp

   1 // RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify %s
   2
   3 // The result of the expression const_cast<T>(v) is of type T. If T is
   4 // an lvalue reference to object type, the result is an lvalue; if T
   5 // is an rvalue reference to object type, the result is an xvalue;.
   6
   7 unsigned int f(int);
   8
   9 struct X {};
  10
  11 template<typename T> T& lvalue();
  12 template<typename T> T&& xvalue();
  13 template<typename T> T prvalue();
  14
  15 void test_classification(const int *ptr, X x) {
  16   int *&&ptr0 = const_cast<int *&&>(ptr);
  17   int *&&ptr1 = const_cast<int *&&>(xvalue<const int*>());
  18   int *&&ptr2 = const_cast<int *&&>(prvalue<const int*>()); // expected-error {{const_cast from rvalue to reference type 'int *&&'}}
  19   X &&ptr3 = const_cast<X&&>(x);
  20   X &&ptr4 = const_cast<X&&>(xvalue<X>());
  21   X &&ptr5 = const_cast<X&&>(prvalue<X>());
  22
  23   int *&ptr6 = const_cast<int *&>(ptr);
  24   int *&ptr7 = const_cast<int *&>(xvalue<const int*>()); // expected-error {{const_cast from rvalue to reference type 'int *&'}}
  25   int *&ptr8 = const_cast<int *&>(prvalue<const int*>()); // expected-error {{const_cast from rvalue to reference type 'int *&'}}
  26   X &ptr9 = const_cast<X&>(x);
  27   X &ptrA = const_cast<X&>(xvalue<X>()); // expected-error {{const_cast from rvalue to reference type 'X &'}}
  28   X &ptrB = const_cast<X&>(prvalue<X>()); // expected-error {{const_cast from rvalue to reference type 'X &'}}
  29 }
  30
  31 struct A {
  32   volatile unsigned ubf : 4;
  33   volatile unsigned uv;
  34   volatile int sv;
  35   void foo();
  36   bool pred();
  37 };
  38
  39 void test(A &a) {
  40   unsigned &t0 = const_cast<unsigned&>(a.ubf); // expected-error {{const_cast from bit-field lvalue to reference type}}
  41   unsigned &t1 = const_cast<unsigned&>(a.foo(), a.ubf); // expected-error {{const_cast from bit-field lvalue to reference type}}
  42   unsigned &t2 = const_cast<unsigned&>(a.pred() ? a.ubf : a.ubf); // expected-error {{const_cast from bit-field lvalue to reference type}}
  43   unsigned &t3 = const_cast<unsigned&>(a.pred() ? a.ubf : a.uv); // expected-error {{const_cast from bit-field lvalue to reference type}}
  44   unsigned &t4 = const_cast<unsigned&>(a.pred() ? a.ubf : a.sv); // expected-error {{const_cast from rvalue to reference type}}
  45 }