1// DR 339
2//
3// Test of the use of the new and new[] operators with SFINAE
4
5// Boilerplate helpers
6typedef char yes_type;
7struct no_type { char data[2]; };
8
9template<typename T> T create_a();
10template<typename T> struct type { };
11
12template<bool, typename T = void> struct enable_if { typedef T type; };
13template<typename T> struct enable_if<false, T> { };
14
15#define JOIN( X, Y ) DO_JOIN( X, Y )
16#define DO_JOIN( X, Y ) DO_JOIN2(X,Y)
17#define DO_JOIN2( X, Y ) X##Y
18
19template<typename T>
20typename enable_if<(sizeof(new T, 0) > 0), yes_type>::type
21  check_new(int);
22
23template<typename T> no_type check_new(...);
24
25template<typename T>
26struct has_new
27{
28  static const bool value =
29    (sizeof(check_new<T>(0)) == sizeof(yes_type));
30};
31
32template<typename T, typename U>
33typename enable_if<(sizeof((new T(create_a<U>())), 0) > 0),
34                   yes_type>::type
35  check_new_one_arg(int);
36
37template<typename T, typename U> no_type check_new_one_arg(...);
38
39template<typename T, typename U>
40struct has_new_one_arg
41{
42  static const bool value =
43    (sizeof(check_new_one_arg<T, U>(0)) == sizeof(yes_type));
44};
45
46template<typename T, typename U, U N>
47typename enable_if<(sizeof(new T[N], 0) > 0), yes_type>::type
48  check_array_new(int);
49
50template<typename T, typename U, U N> no_type check_array_new(...);
51
52template<typename T, typename U, U N>
53struct has_array_new
54{
55  static const bool value =
56    (sizeof(check_array_new<T, U, N>(0)) == sizeof(yes_type));
57};
58
59#ifdef __GXX_EXPERIMENTAL_CXX0X__
60#  define STATIC_ASSERT(Expr) static_assert(Expr, #Expr)
61#else
62#  define STATIC_ASSERT(Expr) int JOIN(a,__LINE__)[Expr? 1 : -1]
63#endif
64
65struct X {
66  X(int);
67};
68
69struct Y { int foo; };
70
71STATIC_ASSERT((has_new<Y>::value));
72STATIC_ASSERT(!(has_new<X>::value));
73STATIC_ASSERT((has_new_one_arg<Y, Y>::value));
74STATIC_ASSERT((has_new_one_arg<X, float>::value));
75STATIC_ASSERT(!(has_new_one_arg<X, int X::*>::value));
76
77STATIC_ASSERT((has_array_new<Y, int, 5>::value));
78STATIC_ASSERT(!(has_array_new<X, int Y::*, &Y::foo>::value));
79STATIC_ASSERT((has_array_new<X, int, 5>::value));
80