ITK  5.3.0
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
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14  * See the License for the specific language governing permissions and
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17  *=========================================================================*/
18 #ifndef itkStructHashFunction_h
19 #define itkStructHashFunction_h
20 
21 #include "itkIntTypes.h"
22 #include "itkMacro.h"
23 
24 namespace itk
25 {
39 template <typename TInput>
41 {
42 public:
45 
47  using InputType = TInput;
48 
50  operator()(const InputType & key) const;
51 };
52 
53 template <typename TInput>
54 inline 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
itk::StructHashFunction::operator()
IdentifierType operator()(const InputType &key) const
Definition: itkStructHashFunction.h:55
itkMacro.h
itk::StructHashFunction::InputType
TInput InputType
Definition: itkStructHashFunction.h:47
itkIntTypes.h
itk
The "itk" namespace contains all Insight Segmentation and Registration Toolkit (ITK) classes....
Definition: itkAnnulusOperator.h:24
itk::StructHashFunction
Generic hash function for an arbitrary struct (or class).
Definition: itkStructHashFunction.h:40
itk::IdentifierType
SizeValueType IdentifierType
Definition: itkIntTypes.h:87