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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 
test_classification(const int * ptr,X x)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 
test(A & a)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 }
46