Add an etl::nullptr_t type to <etl/nullptr.h>

include/etl/memory.h

@@ -1393,7 +1393,7 @@ namespace etl
  }
 
  //*********************************
- void reset(pointer p_ = pointer()) ETL_NOEXCEPT
+ void reset(pointer p_) ETL_NOEXCEPT
  {
  assert(p_ != p);
 
@@ -1406,6 +1406,12 @@ namespace etl
  }
  }
 
+ void reset(etl::nullptr_t p_ = ETL_NULLPTR) ETL_NOEXCEPT
+ {
+ (void)p_; // unused argument
+ reset(pointer());
+ }
+
  //*********************************
  void swap(unique_ptr& value) ETL_NOEXCEPT
  {
@@ -1420,29 +1426,16 @@ namespace etl
  return (p != ETL_NULLPTR);
  }
 
-#if ETL_USING_STL && ETL_USING_CPP11
  //*********************************
- unique_ptr& operator =(std::nullptr_t) ETL_NOEXCEPT
+ unique_ptr& operator =(etl::nullptr_t) ETL_NOEXCEPT
  {
  if (p)
  {
- reset(nullptr);
+ reset(ETL_NULLPTR);
  }
 
  return *this;
  }
-#else
- //*********************************
- unique_ptr& operator =(void*) ETL_NOEXCEPT
- {
- if (p)
- {
- reset(NULL);
- }
-
- return *this;
- }
-#endif
 
 #if ETL_USING_CPP11
  //*********************************

include/etl/nullptr.h

@@ -35,13 +35,33 @@ SOFTWARE.
 
 #include <stddef.h>
 
+namespace etl
+{
 #if ETL_CPP11_NOT_SUPPORTED
- // Use the old style C++ NULL definition.
- #define ETL_NULLPTR 0
+ class nullptr_t
+ {
+ public:
+ template <class T>
+ inline operator T*() const { return 0; }
+
+ template <class C, class T>
+ inline operator T C::* () const { return 0; }
+
+ inline bool operator==(nullptr_t) const { return true; }
+ inline bool operator!=(nullptr_t) const { return false; }
+ private:
+ void operator&() const ETL_DELETE; // cannot take the address of ETL_NULLPTR
+ };
+
+ static const nullptr_t _nullptr = nullptr_t();
+
+ #define ETL_NULLPTR (etl::_nullptr)
 #else
  // Use the new style nullptr.
+ typedef decltype(nullptr) nullptr_t;
  #define ETL_NULLPTR nullptr
 #endif
+}
 
 #endif
 

include/etl/private/addressof.h

@@ -32,6 +32,7 @@ SOFTWARE.
 #define ETL_ADDRESSOF_INCLUDED
 
 #include "../platform.h"
+#include "../type_traits.h"
 
 #if defined(ETL_IN_UNIT_TEST) || ETL_USING_STL
  #include <memory>
@@ -48,7 +49,7 @@ namespace etl
  ///\ingroup memory
  //*****************************************************************************
  template <typename T>
- ETL_CONSTEXPR17 T* addressof(T& t)
+ ETL_CONSTEXPR17 typename etl::enable_if<!etl::is_same<T, etl::nullptr_t>::value, T>::type* addressof(T& t)
  {
 #if ETL_USING_STL && ETL_USING_CPP11
  return std::addressof(t);