Deprecate the DUNE_ASSERT_AND_RETURN macro

CHANGELOG.md

@@ -70,7 +70,8 @@ In order to build the DUNE core modules you need at least the following software
 - Deprecated `conjunction`, `disjunction`, and `negation` have been removed. Instead,
   use the structs from `<type_traits>` introduced with C++17.
 - Remove deprecated `dune/common/std/apply.hh`, use `std::apply` instead.
-
+- Deprecated the file `dune/common/assertandreturn.hh` and the contained utility
+  `DUNE_ASSERT_AND_RETURN`. Use `assert()` macro directly in `constexpr` functions.
 
 # Release 2.9
 

dune/common/assertandreturn.hh

@@ -5,6 +5,10 @@
 #ifndef DUNE_COMMON_ASSERTANDRETURN_HH
 #define DUNE_COMMON_ASSERTANDRETURN_HH
 
+#warning "The file assertandreturn.hh is deprecated. Since c++14 constexpr functions allow more \
+than a single return statement and thus this utility is useless. Will be removed after \
+Dune 2.10 release."
+
 #include <cassert>
 
 //! Asserts a condition and return on success in constexpr context.
@@ -15,6 +19,7 @@
  * and then returns the value of the second argument.
  *
  * \ingroup CxxUtilities
+ * \deprecated Will be removed after Dune 2.10 release
  */
 #ifdef NDEBUG
   #define DUNE_ASSERT_AND_RETURN(C,X) X

dune/common/hybridutilities.hh

@@ -149,14 +149,11 @@ namespace Impl {
     return Dune::StaticIntegralRange<std::size_t, End::value, Begin::value>();
   }
 
-  // This should be constexpr but gcc-4.9 does not support
-  // the relaxed constexpr requirements. Hence for being
-  // constexpr the function body can only contain a return
-  // statement and no assertion before this.
   template<class Begin, class End>
   constexpr auto integralRange(const Begin& begin, const End& end, const PriorityTag<0>&)
   {
-    return DUNE_ASSERT_AND_RETURN(begin<=end, Dune::IntegralRange<End>(begin, end));
+    assert(begin<=end && "You cannot create an integralRange where end<begin");
+    return Dune::IntegralRange<End>(begin, end);
   }
 
 } // namespace Impl