vsg: include/vsg/core/compare.h Source File

vsg 1.1.3 VulkanSceneGraph library

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compare.h
1#pragma once
2
3/* <editor-fold desc="MIT License">
4
5Copyright(c) 2022 Robert Osfield
6
7Permission 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:
8
9The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
10
11THE 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.
12
13</editor-fold> */
14
15#include <vsg/core/ref_ptr.h>
16
17#include <cstring>
18
19namespace vsg
20{
21
22 template<class T, class R>
23 int compare_pointer(const ref_ptr<T>& lhs, const ref_ptr<R>& rhs)
24 {
25 if (lhs == rhs) return 0;
26 return lhs ? (rhs ? lhs->compare(*rhs) : 1) : (rhs ? -1 : 0);
27 }
28
29 template<class T>
30 int compare_value(const T& lhs, const T& rhs)
31 {
32 return (lhs < rhs) ? -1 : ((rhs < lhs) ? 1 : 0);
33 }
34
35 template<class T>
36 int compare_values(const T* lhs, const T* rhs, size_t size)
37 {
38 int result = 0;
39 for (size_t i = 0; i < size; ++i)
40 {
41 if ((result = compare_value(lhs[i], rhs[i]))) break;
42 }
43 return result;
44 }
45
46 template<typename T>
47 int compare_memory(const T& lhs, const T& rhs)
48 {
49 return std::memcmp(&lhs, &rhs, sizeof(T));
50 }
51
52 template<typename S, typename E>
53 int compare_region(const S& start, const E& end, const S& rhs)
54 {
55 const char* lhs_ptr = reinterpret_cast<const char*>(&start);
56 const char* rhs_ptr = reinterpret_cast<const char*>(&rhs);
57 size_t size = size_t(reinterpret_cast<const char*>(&end) - lhs_ptr) + sizeof(E);
58
59 // use memcpy to compare the contents of the data
60 return std::memcmp(lhs_ptr, rhs_ptr, size);
61 }
62
63 template<typename T>
64 int compare_pointer_container(const T& lhs, const T& rhs)
65 {
66 if (lhs.size() < rhs.size()) return -1;
67 if (lhs.size() > rhs.size()) return 1;
68 if (lhs.empty()) return 0;
69
70 auto rhs_itr = rhs.begin();
71 for (auto& object : lhs)
72 {
73 int result = compare_pointer(object, *rhs_itr++);
74 if (result != 0) return result;
75 }
76 return 0;
77 }
78
79 template<typename T>
80 int compare_value_container(const T& lhs, const T& rhs)
81 {
82 if (lhs.size() < rhs.size()) return -1;
83 if (lhs.size() > rhs.size()) return 1;
84 if (lhs.empty()) return 0;
85
86 return compare_region(lhs.front(), lhs.back(), rhs.front());
87 }
88
89 template<typename T>
90 int compare_container(const T& lhs, const T& rhs)
91 {
92 if (lhs.size() < rhs.size()) return -1;
93 if (lhs.size() > rhs.size()) return 1;
94 if (lhs.empty()) return 0;
95
96 auto rhs_itr = rhs.begin();
97 for (auto& object : lhs)
98 {
99 int result = object.compare(*rhs_itr++);
100 if (result != 0) return result;
101 }
102 return 0;
103 }
104
106 struct DereferenceLess
107 {
108 template<class P>
109 bool operator()(const P& lhs, const P& rhs) const
110 {
111 return lhs->compare(*rhs) < 0;
112 }
113 };
114
115} // namespace vsg
vsg::DereferenceLess
less functor for comparing ref_ptr<Object> typically used with std::set<> etc.
Definition compare.h:107
vsg::allocator_affinity_nodes
std container adapter for allocating with MEMORY_AFFINITY_NODES
Definition Allocator.h:138