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
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
|
/* Heap-allocation free & small memory footprint
* std::function alternative with limited capabilities.
*/ // single-header library
/* Copyright (c) 2026 dyknon
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the " Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom
* the Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice
* (including the next paragraph) shall be included in all copies
* or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#ifndef INC_THINFUNC_H
#define INC_THINFUNC_H
namespace tf{
template<class F>
struct func;
template<class R, class... Args>
struct func<R(Args...)>{
virtual R operator()(Args...) const = 0;
};
template<class T, class F>
class anchor;
template<class T, class AT, class MT, AT AV, MT MV>
class bound_anchor;
template<class T, class R, class... Args>
class anchor<T, R(Args...)>{
friend T;
public:
template<anchor<T, R(Args...)> (T::*Self), R (T::*Method)(Args...)>
using bound_type = bound_anchor<T,
anchor<T, R(Args...)> (T::*), R (T::*)(Args...), Self, Method>;
private:
alignas(bound_type<nullptr, nullptr>)
char body[sizeof(bound_type<nullptr, nullptr>)];
protected:
template<anchor<T, R(Args...)> (T::*Self), R (T::*Method)(Args...)>
auto& bind(){
static_assert(sizeof(bound_type<Self, Method>) == sizeof(body));
static_assert(
(func<R(Args...)> *)(bound_type<nullptr, nullptr> *)nullptr
== (func<R(Args...)> *)(bound_type<Self, Method> *)nullptr);
return *(new (body) bound_type<Self, Method>());
}
public:
template<anchor<T, R(Args...)> (T::*Self), R (T::*Method)(Args...)>
auto& bound(){
return *(bound_type<Self, Method> *)body;
}
func<R(Args...)>& bound(){
return *(func<R(Args...)> *)(bound_type<nullptr, nullptr> *)body;
}
anchor(const anchor&) = delete;
anchor(const anchor&&) = delete;
anchor& operator=(const anchor&) = delete;
anchor& operator=(const anchor&&) = delete;
anchor() = default;
};
template<
class T, class R, class... Args,
anchor<T, R(Args...)> (T::*Self), R (T::*Method)(Args...)
>
class bound_anchor<T,
anchor<T, R(Args...)> (T::*), R (T::*)(Args...),
Self, Method
>: public func<R(Args...)>{
public:
bound_anchor(){}
bound_anchor(const bound_anchor&) = delete;
bound_anchor(const bound_anchor&&) = delete;
bound_anchor& operator=(const bound_anchor&) = delete;
bound_anchor& operator=(const bound_anchor&&) = delete;
virtual R operator()(Args... args) const{
auto offset = (char *)&(((T *)0)->*Self) - (char *)0;
T *container = (T *)((char *)this - offset);
return (container->*Method)(args...);
}
};
} // namespace rf
#endif //INC_THINFUNC_H
|
