Shuenhoy/vtk-m
1
0
Fork 0
mirror of https://gitlab.kitware.com/vtk/vtk-m synced 2024-09-18 18:15:44 +00:00
Code Issues 2 Actions Packages Projects Releases Wiki Activity

Merge topic 'backup-aligned-union'

Browse Source 
01176efbd Provide implementation of aligned_union

Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: Allison Vacanti <allison.vacanti@kitware.com>
Merge-request: !1741
This commit is contained in:
Kenneth Moreland 2019-07-30 20:02:43 +00:00 committed by Kitware Robot
commit 023e12b23a
1 changed files with 40 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

41
vtkm/internal/Variant.h
View File

@ -14,6 +14,45 @@
#include <vtkm/ListTag.h>
// It would make sense to put this in its own header file, but it is hard to imagine needing
// aligned_union anywhere else.
#if (defined(VTKM_GCC) && (__GNUC__ == 4)) || (defined(VTKM_ICC) && (__INTEL_COMPILER < 1800))
#include <algorithm>
namespace vtkmstd
{
template <std::size_t... Xs>
struct max_size;
template <std::size_t X>
struct max_size<X>
{
static constexpr std::size_t value = X;
};
template <std::size_t X0, std::size_t... Xs>
struct max_size<X0, Xs...>
{
static constexpr std::size_t other_value = max_size<Xs...>::value;
static constexpr std::size_t value = (other_value > X0) ? other_value : X0;
};
// This implementation comes from https://en.cppreference.com/w/cpp/types/aligned_union
template <std::size_t Len, class... Types>
struct aligned_union
{
static constexpr std::size_t alignment_value = vtkmstd::max_size<alignof(Types)...>::value;
struct type
{
alignas(alignment_value) char _s[vtkmstd::max_size<Len, sizeof(Types)...>::value];
};
};
} // namespace vtkmstd
#else
namespace vtkmstd
{
using std::aligned_union;
} // namespace vtkmstd
#endif
namespace vtkm
{
namespace internal
@ -51,7 +90,7 @@ class Variant
{
};
typename std::aligned_union<0, Ts...>::type Storage;
typename vtkmstd::aligned_union<0, Ts...>::type Storage;
VTKM_EXEC_CONT void* GetPointer() { return reinterpret_cast<void*>(&this->Storage); }
VTKM_EXEC_CONT const void* GetPointer() const