PointerLikeTypeTraits.h [plain text]
#ifndef LLVM_SUPPORT_POINTERLIKETYPETRAITS_H
#define LLVM_SUPPORT_POINTERLIKETYPETRAITS_H
#include "llvm/Support/AlignOf.h"
#include "llvm/Support/DataTypes.h"
namespace llvm {
template <typename T> class PointerLikeTypeTraits {
};
namespace detail {
template <size_t N>
struct ConstantLog2
: std::integral_constant<size_t, ConstantLog2<N / 2>::value + 1> {};
template <> struct ConstantLog2<1> : std::integral_constant<size_t, 0> {};
}
template <typename T> struct PointerLikeTypeTraits<T *> {
static inline void *getAsVoidPointer(T *P) { return P; }
static inline T *getFromVoidPointer(void *P) { return static_cast<T *>(P); }
enum {
NumLowBitsAvailable = detail::ConstantLog2<AlignOf<T>::Alignment>::value
};
};
template <> struct PointerLikeTypeTraits<void *> {
static inline void *getAsVoidPointer(void *P) { return P; }
static inline void *getFromVoidPointer(void *P) { return P; }
enum { NumLowBitsAvailable = 2 };
};
template <typename T> class PointerLikeTypeTraits<const T *> {
typedef PointerLikeTypeTraits<T *> NonConst;
public:
static inline const void *getAsVoidPointer(const T *P) {
return NonConst::getAsVoidPointer(const_cast<T *>(P));
}
static inline const T *getFromVoidPointer(const void *P) {
return NonConst::getFromVoidPointer(const_cast<void *>(P));
}
enum { NumLowBitsAvailable = NonConst::NumLowBitsAvailable };
};
template <> class PointerLikeTypeTraits<uintptr_t> {
public:
static inline void *getAsVoidPointer(uintptr_t P) {
return reinterpret_cast<void *>(P);
}
static inline uintptr_t getFromVoidPointer(void *P) {
return reinterpret_cast<uintptr_t>(P);
}
enum { NumLowBitsAvailable = 0 };
};
}
#endif