|
111
|
1 // DR 339
|
|
|
2 //
|
|
|
3 // Test of the use of the function call operator with SFINAE
|
|
|
4 typedef char yes_type;
|
|
|
5 struct no_type { char data[2]; };
|
|
|
6
|
|
|
7 template<typename T> T create_a();
|
|
|
8
|
|
|
9 template<typename T> struct type { };
|
|
|
10
|
|
|
11 template<bool, typename T = void> struct enable_if { typedef T type; };
|
|
|
12 template<typename T> struct enable_if<false, T> { };
|
|
|
13
|
|
|
14 template<typename F, typename T1, typename T2>
|
|
|
15 typename enable_if<sizeof(create_a<F>()(create_a<T1>(), create_a<T2>()), 1),
|
|
|
16 yes_type>::type
|
|
|
17 check_is_callable2(type<F>, type<T1>, type<T2>);
|
|
|
18
|
|
|
19 no_type check_is_callable2(...);
|
|
|
20
|
|
|
21 template<typename F, typename T1, typename T2 = T1>
|
|
|
22 struct is_callable2
|
|
|
23 {
|
|
|
24 static const bool value =
|
|
|
25 (sizeof(check_is_callable2(type<F>(), type<T1>(), type<T2>()))
|
|
|
26 == sizeof(yes_type));
|
|
|
27 };
|
|
|
28
|
|
|
29 #define JOIN( X, Y ) DO_JOIN( X, Y )
|
|
|
30 #define DO_JOIN( X, Y ) DO_JOIN2(X,Y)
|
|
|
31 #define DO_JOIN2( X, Y ) X##Y
|
|
|
32
|
|
|
33 #ifdef __GXX_EXPERIMENTAL_CXX0X__
|
|
|
34 # define STATIC_ASSERT(Expr) static_assert(Expr, #Expr)
|
|
|
35 #else
|
|
|
36 # define STATIC_ASSERT(Expr) int JOIN(a,__LINE__)[Expr? 1 : -1]
|
|
|
37 #endif
|
|
|
38
|
|
|
39
|
|
|
40 struct A;
|
|
|
41 struct B;
|
|
|
42
|
|
|
43 struct A {
|
|
|
44 A(B);
|
|
|
45 };
|
|
|
46
|
|
|
47 struct B {
|
|
|
48 B(A);
|
|
|
49 };
|
|
|
50
|
|
|
51 struct F {
|
|
|
52 void operator()(A, A);
|
|
|
53
|
|
|
54 private:
|
|
|
55 void operator()(B, B);
|
|
|
56 };
|
|
|
57
|
|
|
58 STATIC_ASSERT((!is_callable2<F, B, B>::value));
|
