1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
|
// { dg-options "-std=gnu++0x" }
#define ONE
#define TWO
#define THREE
struct Something {};
Something ___;
template <class F>
struct Trial
{
F f;
public:
Trial() : f() {}
Trial( const F& ff ) : f(ff) { }
template <typename... Args>
struct Sig { typedef int ResultType; };
template <typename... Args>
struct Sig<Something,Args...> { typedef int ResultType; };
#ifdef ONE
template <typename... Args>
typename Sig<Something,Args...>::ResultType operator()(const Something& s, const Args&... args) const
{
return f(args...);
}
#endif
#ifdef TWO
template <typename... Args>
typename Sig<Args...>::ResultType operator()(const Args&... args) const
{
return f(args...);
}
#endif
};
struct Internal
{
template <typename... Args>
struct Sig { typedef int ResultType; };
template <typename... Args>
struct Sig<Something,Args...> { typedef int ResultType; };
template <typename... Args>
int operator()(const Args&... args) const
{
int n = sizeof...(Args);
return n;
}
static Trial<Internal>& full() { static Trial<Internal> f; return f; }
};
static Trial<Internal>& internal = Internal::full();
int main()
{
int n = 0;
#ifdef ONE
n = internal(___,1,2);
#endif
#ifdef THREE
n = internal(___,1,2,3);
n = internal(___,1,2,3,4);
#endif
return 0;
}
|
