test/SemaCXX/references.cpp

   1 // RUN: clang-cc -fsyntax-only -verify %s
   2 int g(int);
   3
   4 void f() {
   5   int i;
   6   int &r = i;
   7   r = 1;
   8   int *p = &r;
   9   int &rr = r;
  10   int (&rg)(int) = g;
  11   rg(i);
  12   int a[3];
  13   int (&ra)[3] = a;
  14   ra[1] = i;
  15   int *Q;
  16   int *& P = Q;
  17   P[1] = 1;
  18 }
  19
  20 typedef int t[1];
  21 void test2() {
  22     t a;
  23     t& b = a;
  24
  25
  26     int c[3];
  27     int (&rc)[3] = c;
  28 }
  29
  30 // C++ [dcl.init.ref]p5b1
  31 struct A { };
  32 struct B : A { } b;
  33
  34 void test3() {
  35   double d = 2.0;
  36   double& rd = d; // rd refers to d
  37   const double& rcd = d; // rcd refers to d
  38
  39   A& ra = b; // ra refers to A subobject in b
  40   const A& rca = b; // rca refers to A subobject in b
  41 }
  42
  43 B fB();
  44
  45 // C++ [dcl.init.ref]p5b2
  46 void test4() {
  47   double& rd2 = 2.0; // expected-error{{non-const lvalue reference to type 'double' cannot be initialized with a temporary of type 'double'}}
  48   int i = 2;
  49   double& rd3 = i; // expected-error{{non-const lvalue reference to type 'double' cannot be initialized with a value of type 'int'}}
  50
  51   const A& rca = fB();
  52 }
  53
  54 void test5() {
  55   const double& rcd2 = 2; // rcd2 refers to temporary with value 2.0
  56   const volatile int cvi = 1;
  57   const int& r = cvi; // expected-error{{initialization of reference to type 'int const' with a value of type 'int const volatile' drops qualifiers}}
  58 }
  59
  60 // C++ [dcl.init.ref]p3
  61 int& test6(int& x) {
  62   int& yo; // expected-error{{declaration of reference variable 'yo' requires an initializer}}
  63
  64   return x;
  65 }
  66 int& not_initialized_error; // expected-error{{declaration of reference variable 'not_initialized_error' requires an initializer}}
  67 extern int& not_initialized_okay;
  68
  69 class Test6 {
  70   int& okay;
  71 };
  72
  73 struct C : B, A { };
  74
  75 void test7(C& c) {
  76   A& a1 = c; // expected-error {{ambiguous conversion from derived class 'struct C' to base class 'struct A':}}
  77 }
  78
  79 // C++ [dcl.ref]p1, C++ [dcl.ref]p4
  80 void test8(int& const,// expected-error{{'const' qualifier may not be applied to a reference}}
  81
  82            void&,     // expected-error{{cannot form a reference to 'void'}}
  83            int& &)    // expected-error{{type name declared as a reference to a reference}}
  84 {
  85   typedef int& intref;
  86   typedef intref& intrefref; // C++ DR 106: reference collapsing
  87
  88   typedef intref const intref_c; // okay. FIXME: how do we verify that this is the same type as intref?
  89 }