vtkMeta.h

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// SPDX-FileCopyrightText: Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
// SPDX-License-Identifier: BSD-3-Clause
 
#ifndef vtkMeta_h
#define vtkMeta_h
 
#include "vtkABINamespace.h"
 
#include <type_traits>
#include <utility>
 
// Forward decs for StripPointers:
VTK_ABI_NAMESPACE_BEGIN
template <typename ArrayType>
class vtkNew;
template <typename ArrayType>
class vtkSmartPointer;
template <typename ArrayType>
class vtkWeakPointer;
VTK_ABI_NAMESPACE_END
 
namespace vtk
{
namespace detail
{
VTK_ABI_NAMESPACE_BEGIN
 
//------------------------------------------------------------------------------
// Strip vtkNew, vtkSmartPointer, etc from a type.
template <typename T>
struct StripPointers
{
  using type = T;
};
 
template <typename T>
struct StripPointers<T*>
{
  using type = T;
};
 
template <typename ArrayType>
struct StripPointers<vtkNew<ArrayType>>
{
  using type = ArrayType;
};
 
template <typename ArrayType>
struct StripPointers<vtkSmartPointer<ArrayType>>
{
  using type = ArrayType;
};
 
template <typename ArrayType>
struct StripPointers<vtkWeakPointer<ArrayType>>
{
  using type = ArrayType;
};
 
//------------------------------------------------------------------------------
// Test if a type is defined (true) or just forward declared (false).
template <typename T>
struct IsComplete
{
private:
  // Can't take the sizeof an incomplete class.
  template <typename U, std::size_t = sizeof(U)>
  static std::true_type impl(U*);
  static std::false_type impl(...);
  using bool_constant = decltype(impl(std::declval<T*>()));
 
public:
  static constexpr bool value = bool_constant::value;
};
 
VTK_ABI_NAMESPACE_END
}
} // end namespace vtk::detail
 
#endif // vtkMeta_h
 
// VTK-HeaderTest-Exclude: vtkMeta.h