default-arguments.cpp revision 7bb87fca7d22a8a194d04188746b90f46512975f 
1// RUN: clang-cc -fsyntax-only -verify %s
2template<typename T, int N = 2> struct X; // expected-note{{template is declared here}}
3
4X<int, 1> *x1;
5X<int> *x2;
6
7X<> *x3; // expected-error{{too few template arguments for class template 'X'}}
8
9template<typename U = float, int M> struct X;
10
11X<> *x4;
12
13template<typename T = int> struct Z { };
14template struct Z<>;
15
16// PR4362
17template<class T> struct a { };
18template<> struct a<int> { static const bool v = true; };
19
20template<class T, bool = a<T>::v> struct p { }; // expected-error {{no member named 'v'}}
21
22template struct p<bool>; // expected-note {{in instantiation of default argument for 'p<bool>' required here}}
23template struct p<int>;
24
25// PR5187
26template<typename T, typename U>
27struct A;
28
29template<typename T, typename U = T>
30struct A;
31
32template<typename T, typename U>
33struct A {
34  void f(A<T>);
35};
36
37template<typename T>
38struct B { };
39
40template<>
41struct B<void> {
42  typedef B<void*> type;
43};
44
45// Nested default arguments for template parameters.
46template<typename T> struct X1 { };
47
48template<typename T>
49struct X2 {
50  template<typename U = typename X1<T>::type> // expected-error{{no type named}}
51  struct Inner1 { };
52
53  template<T Value = X1<T>::value> // expected-error{{no member named 'value'}}
54  struct NonType1 { };
55
56  template<T Value>
57  struct Inner2 { };
58
59  template<typename U>
60  struct Inner3 {
61    template<typename X = T, typename V = U>
62    struct VeryInner { };
63
64    template<T Value1 = sizeof(T), T Value2 = sizeof(U),
65             T Value3 = Value1 + Value2>
66    struct NonType2 { };
67  };
68};
69
70X2<int> x2i;
71X2<int>::Inner1<float> x2iif;
72
73X2<int>::Inner1<> x2bad; // expected-note{{instantiation of default argument}}
74
75X2<int>::NonType1<'a'> x2_nontype1;
76X2<int>::NonType1<> x2_nontype1_bad; // expected-note{{instantiation of default argument}}
77
78// Check multi-level substitution into template type arguments
79X2<int>::Inner3<float>::VeryInner<> vi;
80X2<char>::Inner3<int>::NonType2<> x2_deep_nontype;
81
82template<typename T, typename U>
83struct is_same { static const bool value = false; };
84
85template<typename T>
86struct is_same<T, T> { static const bool value = true; };
87
88int array1[is_same<__typeof__(vi),
89               X2<int>::Inner3<float>::VeryInner<int, float> >::value? 1 : -1];
90
91int array2[is_same<__typeof(x2_deep_nontype),
92                   X2<char>::Inner3<int>::NonType2<sizeof(char), sizeof(int),
93                                    sizeof(char)+sizeof(int)> >::value? 1 : -1];
94
95// Template template parameter defaults
96template<template<typename T> class X = X2> struct X3 { };
97int array3[is_same<X3<>, X3<X2> >::value? 1 : -1];
98
99struct add_pointer {
100  template<typename T>
101  struct apply {
102    typedef T* type;
103  };
104};
105
106template<typename T, template<typename> class X = T::template apply>
107  struct X4;
108int array4[is_same<X4<add_pointer>,
109                   X4<add_pointer, add_pointer::apply> >::value? 1 : -1];
110