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/*=========================================================================
*
* Copyright NumFOCUS
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0.txt
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*=========================================================================*/
#ifndef itkDeref_h
#define itkDeref_h
#include "itkMacro.h"
#include <string>
#include <typeinfo>
namespace itk
{
/** \class DerefError
* Exception thrown when trying to dereference a null pointer.
* \ingroup ITKCommon
*/
class DerefError : public ExceptionObject
{
public:
// Inherit the constructors from its base class.
using ExceptionObject::ExceptionObject;
/** \see LightObject::GetNameOfClass() */
itkOverrideGetNameOfClassMacro(DerefError);
};
/** Dereferences the specified pointer, when the pointer is not null. Throws a `DerefError` exception when the pointer
* is null. Aims to avoid undefined behavior from accidentally dereferencing a null pointer.
*/
template <typename T>
T &
Deref(T * const ptr)
{
if (ptr == nullptr)
{
itkSpecializedMessageExceptionMacro(
DerefError, "The pointer passed to `itk::Deref(T*)` is null! T's typeid name: `" << typeid(T).name() << '`');
}
return *ptr;
}
} // namespace itk
#endif
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