Merge branch 'feature/FS1042-range-based-for-loops-test-and-iteratorrange'

This branch contains required infrastructure for the new iterator ranges
in dune-grid. In particular, it adds a configuration test that checks
whether the compiler supports range-based for loops and a small utility
class that serves as a container for a pair of begin and end iterators.

* feature/FS1042-range-based-for-loops-test-and-iteratorrange:
  [buildsystem] Check for range-based for.
  [Iterators] Add IteratorRange helper class

cmake/modules/CheckCXX11Features.cmake

@@ -9,6 +9,7 @@
 # HAS_ATTRIBUTE_DEPRECATED_MSG     True if attribute deprecated("msg") is supported
 # HAVE_CONSTEXPR                   True if constexpr is supported
 # HAVE_KEYWORD_FINAL               True if final is supported.
+# HAVE_RANGE_BASED_FOR             True if range-based for is supported and working.
 
 include(CMakePushCheckState)
 cmake_push_check_state()
@@ -166,4 +167,15 @@ check_cxx_source_compiles("
 " HAVE_KEYWORD_FINAL
 )
 
+# range-based for
+check_cxx_source_compiles("
+  int main(void)
+  {
+    int arr[3];
+    for(int &val : arr)
+      val = 0;
+  }
+" HAVE_RANGE_BASED_FOR
+)
+
 cmake_pop_check_state()

dune/common/CMakeLists.txt

@@ -62,6 +62,7 @@ install(FILES
         interfaces.hh
         ios_state.hh
         iteratorfacades.hh
+        iteratorrange.hh
         lcm.hh
         lru.hh
         mallocallocator.hh

dune/common/Makefile.am

@@ -58,6 +58,7 @@ commoninclude_HEADERS = 			\
 	interfaces.hh				\
 	ios_state.hh				\
 	iteratorfacades.hh			\
+	iteratorrange.hh			\
 	lcm.hh					\
 	lru.hh					\
 	mallocallocator.hh			\

dune/common/iteratorrange.hh

+// -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+// vi: set et ts=4 sw=2 sts=2:
+#ifndef DUNE_COMMON_ITERATORRANGE_HH
+#define DUNE_COMMON_ITERATORRANGE_HH
+
+namespace Dune {
+
+  //! Simple range between a begin and an end iterator.
+  /**
+   * IteratorRange is mainly useful as a lightweight adaptor
+   * class when adding support for range-based for loops to
+   * existing containers that lack a standard begin(), end()
+   * pair of member functions.
+   *
+   * \tparam Iterator  The type of iterator
+   */
+  template<typename Iterator>
+  class IteratorRange
+  {
+
+  public:
+
+    //! The iterator belonging to this range.
+    typedef Iterator iterator;
+
+    //! Constructs an iterator range on [begin,end).
+    IteratorRange(const Iterator& begin, const Iterator& end)
+      : _begin(begin)
+      , _end(end)
+    {}
+
+    //! Returns an iterator pointing to the begin of the range.
+    iterator begin() const
+    {
+      return _begin;
+    }
+
+    //! Returns an iterator pointing past the end of the range.
+    iterator end() const
+    {
+      return _end;
+    }
+
+  private:
+
+    const Iterator _begin;
+    const Iterator _end;
+
+  };
+
+}
+
+#endif // DUNE_COMMON_ITERATORRANGE_HH

m4/CMakeLists.txt

@@ -11,6 +11,7 @@ install(PROGRAMS
         cxx0x_nullptr.m4
         cxx11_constexpr.m4
         cxx11_final.m4
+        cxx11_range_based_for.m4
         dune.m4
         dune_all.m4
         dune_autobuild.m4

m4/Makefile.am

@@ -14,6 +14,7 @@ ALLM4S = 					\
 	cxx0x_nullptr.m4			\
 	cxx11_constexpr.m4			\
 	cxx11_final.m4				\
+	cxx11_range_based_for.m4		\
 	dune.m4					\
 	dune_all.m4				\
 	dune_autobuild.m4			\

m4/cxx11_range_based_for.m4

+# tests for C++11 range-based for support
+# the associated define is called HAVE_RANGE_BASED_FOR
+
+AC_DEFUN([DUNE_CXX11_RANGE_BASED_FOR],[
+  AC_CACHE_CHECK([for C++11 range-based for], [dune_cv_cxx11_range_based_for_support], [
+    AC_REQUIRE([AC_PROG_CXX])
+    AC_REQUIRE([CXX11])
+    AC_LANG_PUSH([C++])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM(,[[
+          int arr[3];
+          for(int &val : arr)
+            val = 0;
+        ]])],
+      [dune_cv_cxx11_range_based_for_support=yes],
+      [dune_cv_cxx11_range_based_for_support=no])
+    AC_LANG_POP
+  ])
+  if test "x$dune_cv_cxx11_range_based_for_support" = xyes; then
+    AC_DEFINE([HAVE_RANGE_BASED_FOR], [1], [Define to 1 if C++11 range-based for is supported])
+  fi
+])

m4/dune_common.m4

@@ -21,6 +21,7 @@ AC_DEFUN([DUNE_COMMON_CHECKS],
   AC_REQUIRE([CXX11])
   AC_REQUIRE([NULLPTR_CHECK])
   AC_REQUIRE([CXX11_CONSTEXPR_CHECK])
+  AC_REQUIRE([DUNE_CXX11_RANGE_BASED_FOR])
   AC_REQUIRE([DUNE_BOOST_BASE])
   AC_REQUIRE([DUNE_LINKCXX])
   AC_REQUIRE([DUNE_CHECKDEPRECATED])