xnu-7195.101.1.tar.gz

[apple/xnu.git] / libkern / os / cpp_util.h

diff --git a/libkern/os/cpp_util.h b/libkern/os/cpp_util.h
index dc7236bff098212b1fe7a64b9568e119c97acb16..5821f1f08bfdf24d3f05d12d933e478610ed246c 100644 (file)
--- a/libkern/os/cpp_util.h
+++ b/libkern/os/cpp_util.h
@@ -11,6 +11,8 @@
 # define OS_HAS_RVALUE_REFERENCES 1
 #endif
 
+void* operator new(size_t, void*);
+
 namespace os {
 #if OS_HAS_NULLPTR
 typedef decltype(nullptr) nullptr_t;
@@ -33,6 +35,9 @@ template <class _T> struct remove_const           {typedef _T type;};
 template <class _T> struct remove_const<const _T> {typedef _T type;};
 template <class _T> using remove_const_t = typename remove_const<_T>::type;
 
+template <class T> struct is_lvalue_reference { static constexpr bool value = false; };
+template <class T> struct is_lvalue_reference<T&> { static constexpr bool value = true; };
+
 /*
  * Move
  */
@@ -44,6 +49,69 @@ move(_T && _t)
        typedef typename os::remove_reference<_T>::type _U;
        return static_cast<_U &&>(_t);
 }
+
+template <class T>
+T*
+move(T* first, T* last, T* d_first)
+{
+       for (; first != last; ++d_first, (void)++first) {
+               *d_first = os::move(*first);
+       }
+       return d_first;
+}
+
+template <class T>
+constexpr T && forward(os::remove_reference_t<T>&t) noexcept {
+       return static_cast<T &&>(t);
+}
+
+template <class T>
+constexpr T && forward(os::remove_reference_t<T>&& t) noexcept {
+       static_assert(!os::is_lvalue_reference<T>::value,
+           "can not forward an rvalue as an lvalue");
+       return static_cast<T &&>(t);
+}
+
+// Moves [first, last) into the range ending at d_last,
+// proceeding backwards (from last to first)
+// UB if d_last is within (first, last]
+template <class T>
+T*
+move_backward(T* first, T* last, T* d_last)
+{
+       while (first != last) {
+               *(--d_last) = os::move(*(--last));
+       }
+       return d_last;
+}
+
+template <class T>
+T*
+uninitialized_move(T* first, T* last, T* d_first)
+{
+       for (; first != last; ++d_first, (void) ++first) {
+               ::new (static_cast<void*>(d_first)) T(os::move(*first));
+       }
+       return first;
+}
+
+template <class T>
+void
+destroy(T* first, T* last)
+{
+       for (; first != last; ++first) {
+               first->~T();
+       }
+}
+
+template <class T>
+void
+uninitialized_value_construct(T* first, T* last)
+{
+       for (; first != last; ++first) {
+               ::new (static_cast<void*>(first)) T();
+       }
+}
 }
 
 #endif /* _OS_CPP_UTIL_H */