ITK  6.0.0
Insight Toolkit
itkStructHashFunction.h
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1/*=========================================================================
2 *
3 * Copyright NumFOCUS
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 * https://www.apache.org/licenses/LICENSE-2.0.txt
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 *
17 *=========================================================================*/
18#ifndef itkStructHashFunction_h
19#define itkStructHashFunction_h
20
21#include "itkIntTypes.h"
22#include "itkMacro.h"
23
24namespace itk
25{
39template <typename TInput>
41{
42public:
45
47 using InputType = TInput;
48
50 operator()(const InputType & key) const;
51};
52
53template <typename TInput>
54inline IdentifierType
56{
57 auto len = static_cast<IdentifierType>(sizeof(InputType));
58 const auto * p = reinterpret_cast<const char *>(&key);
59 IdentifierType hash = 0UL;
60 while (len--)
61 {
62 hash = hash * 65UL + static_cast<IdentifierType>(*p++);
63 }
64 hash += (hash >> 5);
65 return hash;
66}
67} // namespace itk
68
69#endif // ndef itkStructHashFunction_h
Generic hash function for an arbitrary struct (or class).
IdentifierType operator()(const InputType &key) const
The "itk" namespace contains all Insight Segmentation and Registration Toolkit (ITK) classes....
SizeValueType IdentifierType
Definition: itkIntTypes.h:90