libkern/os/cpp_util.h

   1 #ifndef _OS_CPP_UTIL_H
   2 #define _OS_CPP_UTIL_H
   3
   4 #include <sys/cdefs.h>
   5
   6 #if __has_feature(cxx_nullptr) && __has_feature(cxx_decltype)
   7 # define OS_HAS_NULLPTR 1
   8 #endif
   9
  10 #if __has_feature(cxx_rvalue_references) || __has_extension(cxx_rvalue_references)
  11 # define OS_HAS_RVALUE_REFERENCES 1
  12 #endif
  13
  14 namespace os {
  15 #if OS_HAS_NULLPTR
  16 typedef decltype(nullptr) nullptr_t;
  17 #endif
  18
  19 /*
  20  * Reference removal
  21  */
  22
  23 template <class _T> struct remove_reference       {typedef _T type;};
  24 template <class _T> struct remove_reference<_T&>  {typedef _T type;};
  25 template <class _T> struct remove_reference<_T &&> {typedef _T type;};
  26 template <class _T> using remove_reference_t = typename remove_reference<_T>::type;
  27
  28 /*
  29  * Const removal
  30  */
  31
  32 template <class _T> struct remove_const           {typedef _T type;};
  33 template <class _T> struct remove_const<const _T> {typedef _T type;};
  34 template <class _T> using remove_const_t = typename remove_const<_T>::type;
  35
  36 /*
  37  * Move
  38  */
  39
  40 template <class _T>
  41 inline typename remove_reference<_T>::type &&
  42 move(_T && _t)
  43 {
  44         typedef typename os::remove_reference<_T>::type _U;
  45         return static_cast<_U &&>(_t);
  46 }
  47 }
  48
  49 #endif /* _OS_CPP_UTIL_H */