ITK
4.1.0
Insight Segmentation and Registration Toolkit
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00001 /*========================================================================= 00002 * 00003 * Copyright Insight Software Consortium 00004 * 00005 * Licensed under the Apache License, Version 2.0 (the "License"); 00006 * you may not use this file except in compliance with the License. 00007 * You may obtain a copy of the License at 00008 * 00009 * http://www.apache.org/licenses/LICENSE-2.0.txt 00010 * 00011 * Unless required by applicable law or agreed to in writing, software 00012 * distributed under the License is distributed on an "AS IS" BASIS, 00013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 00014 * See the License for the specific language governing permissions and 00015 * limitations under the License. 00016 * 00017 *=========================================================================*/ 00018 #ifndef __itkStructHashFunction_h 00019 #define __itkStructHashFunction_h 00020 00021 #include "itkIntTypes.h" 00022 #include "itkMacro.h" 00023 00024 namespace itk 00025 { 00039 template< class TInput > 00040 class ITK_EXPORT StructHashFunction 00041 { 00042 public: 00043 00045 typedef StructHashFunction Self; 00046 00048 typedef TInput InputType; 00049 00050 IdentifierType operator()(const InputType & key) const; 00051 }; 00052 00053 template< class TInput > 00054 inline IdentifierType 00055 StructHashFunction< TInput > 00056 ::operator()(const InputType & key) const 00057 { 00058 IdentifierType len = static_cast< IdentifierType >( sizeof( InputType ) ); 00059 const char * p = reinterpret_cast< const char * >( &key ); 00060 IdentifierType hash = 0; 00061 while ( len-- ) 00062 { 00063 hash = hash * 65 + *p++; 00064 } 00065 hash += ( hash >> 5 ); 00066 return hash; 00067 } 00068 } 00069 00070 #endif // ndef itkStructHashFunction_h 00071