Merge branch 'bugfix/disableCopyMove-empty-args' into 'master'

fix disableCopyMove for empty arguments

See merge request dune-common!383

dune/common/test/CMakeLists.txt

@@ -256,6 +256,8 @@ dune_add_test(SOURCES to_unique_ptrtest.cc
 
 dune_add_test(SOURCES tupleutilitytest.cc)
 
+dune_add_test(SOURCES typeutilitytest.cc)
+
 dune_add_test(SOURCES typelisttest.cc
               LINK_LIBRARIES dunecommon)
 

dune/common/test/typeutilitytest.cc

+// -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+// vi: set et ts=4 sw=2 sts=2:
+
+#if HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <type_traits>
+
+#include <dune/common/typeutilities.hh>
+
+//////////////////////////////////////////////////////////////////////
+//
+// check disableCopyMove
+//
+
+struct Foo {
+
+    template< class ...Args, Dune::disableCopyMove< Foo, Args ... > = 0 >
+    Foo( Args&& ... )
+    {}
+
+    Foo( const Foo& ) = delete;
+    Foo( Foo&& ) = delete;
+};
+
+static_assert( std::is_default_constructible< Foo >::value, "Foo is not default constructible." );
+static_assert( not std::is_copy_constructible< Foo >::value, "Foo is copy constructible." );
+static_assert( not std::is_move_constructible< Foo >::value, "Foo is move constructible." );
+
+int main()
+{}

dune/common/typeutilities.hh

@@ -17,6 +17,19 @@ namespace Dune {
    */
 
 
+  namespace Impl
+  {
+
+    template<class This, class... T>
+    struct disableCopyMoveHelper : public std::is_base_of<This, std::tuple_element_t<0, std::tuple<std::decay_t<T>...>>>
+    {};
+
+    template<class This>
+    struct disableCopyMoveHelper<This> : public std::false_type
+    {};
+
+  } // namespace Impl
+
 
   /**
    * \brief Helper to disable constructor as copy and move constructor
@@ -27,9 +40,7 @@ namespace Dune {
    * overload set for copy and move constructor or assignment.
    */
   template<class This, class... T>
-  using disableCopyMove = typename std::enable_if<
-    (not(std::is_same<This, typename std::tuple_element<0, std::tuple<typename std::decay<T>::type...> >::type >::value)
-    and not(std::is_base_of<This, typename std::tuple_element<0, std::tuple<typename std::decay<T>::type...> >::type >::value)), int>::type;
+  using disableCopyMove = std::enable_if_t< not Impl::disableCopyMoveHelper<This, T...>::value, int>;