[!686] deprecate `make_unique` fallback implementation

Merge branch 'deprecate-make_unique-fallback' into 'master'

ref:core/dune-common Closes: [#97]

See merge request [!686]

  [#97]: gitlab.dune-project.org/NoneNone/issues/97
  [!686]: gitlab.dune-project.org/core/dune-common/merge_requests/686


Closes #97

cmake/modules/CheckCXXFeatures.cmake

@@ -523,12 +523,6 @@ check_include_file_cxx(
   DUNE_HAVE_HEADER_EXPERIMENTAL_TYPE_TRAITS
   )
 
-check_cxx_symbol_exists(
-  "std::make_unique<int>"
-  memory
-  DUNE_HAVE_CXX_MAKE_UNIQUE
-  )
-
 check_cxx_symbol_exists(
   "std::move<std::bool_constant<true>>"
   "utility;type_traits"

config.h.cmake

@@ -41,9 +41,6 @@
 /* does the standard library provide <experimental/type_traits> ? */
 #cmakedefine DUNE_HAVE_HEADER_EXPERIMENTAL_TYPE_TRAITS 1
 
-/* does the standard library provide make_unique() ? */
-#cmakedefine DUNE_HAVE_CXX_MAKE_UNIQUE 1
-
 /* does the standard library provide bool_constant ? */
 #cmakedefine DUNE_HAVE_CXX_BOOL_CONSTANT 1
 

dune/common/std/memory.hh

@@ -3,8 +3,9 @@
 #ifndef DUNE_COMMON_STD_MEMORY_HH
 #define DUNE_COMMON_STD_MEMORY_HH
 
+#warning dune/common/std/memory.hh is deprecated; use std::make_unique from <memory> instead
+
 #include <memory>
-#include <utility>
 
 namespace Dune
 {
@@ -12,95 +13,8 @@ namespace Dune
   namespace Std
   {
 
-#if DUNE_HAVE_CXX_MAKE_UNIQUE
-
     using std::make_unique;
 
-#else
-
-#ifndef DOXYGEN
-
-    namespace Impl {
-
-      // Helper struct to distinguish non-array, unknown bound
-      // array, and known bound array types using SFINAE
-      // following proposal N3656 by Stephan T. Lavavej.
-
-      template<class T>
-      struct MakeUniqueHelper
-      {
-        typedef std::unique_ptr<T> NonArrayUniquePtr;
-      };
-
-      template<class T>
-      struct MakeUniqueHelper<T[]>
-      {
-        typedef std::unique_ptr<T[]> UnknownBoundArrayUniquePtr;
-        typedef T RawType;
-      };
-
-      template<class T, size_t N>
-      struct MakeUniqueHelper<T[N]>
-      {
-        typedef void KnownBoundArrayUniquePtr;
-      };
-
-    }
-
-#endif // DOXYGEN
-
-    /** \brief Implementation of std::make_unique to be introduced in C++14
-     *
-     *  \tparam  T Nonarray type of object to be constructed
-     *  \tparam  ...Args Parameter types for constructor of T
-     *
-     *  \param args Arguments to be passed to constructor of T
-     *
-     *  This fallback implementation using perfect forwarding
-     *  as proposed by Herb Sutter in http://herbsutter.com/gotw/_102/
-     *
-     * \ingroup CxxUtilities
-     */
-    template<typename T, typename... Args>
-    typename Impl::MakeUniqueHelper<T>::NonArrayUniquePtr
-      make_unique(Args&&... args)
-    {
-      return std::unique_ptr<T>(new T(std::forward<Args>(args)...));
-    }
-
-    /** \brief Implementation of std::make_unique to be introduced in C++14
-     *
-     *  \tparam  T Array type of unknown bound
-     *
-     *  \param  n Size of array to allocate
-     *
-     * \ingroup CxxUtilities
-     */
-    template<typename T>
-    typename Impl::MakeUniqueHelper<T>::UnknownBoundArrayUniquePtr
-      make_unique(size_t n)
-    {
-      return std::unique_ptr<T>(new typename Impl::MakeUniqueHelper<T>::RawType[n]());
-    }
-
-    /** \brief Implementation of std::make_unique to be introduced in C++14
-     *
-     *  \tparam  T Array type of known bound
-     *  \tparam  Args Dummy arguments
-     *
-     *  This is deleted, since, according to the standard this should not
-     *  participate in overload resolution
-     *
-     *  \param args Dummy arguments
-     *
-     * \ingroup CxxUtilities
-     */
-    template<typename T, typename ...Args>
-    typename Impl::MakeUniqueHelper<T>::KnownBoundArrayUniquePtr
-      make_unique(Args&&... args) = delete;
-
-#endif // DUNE_HAVE_CXX_MAKE_UNIQUE
-
   } // namespace Std
 
 } // namespace Dune