Check that iterator<T> can be compared with iterator<const T> as soon as a

conversion from iterator<T> to iterator<const T> exists (currently fails)

[[Imported from SVN: r5673]]

dune/common/test/Makefile.am

@@ -2,7 +2,7 @@
 # $Id$
 
 TESTPROGS = parsetest test-stack arraylisttest smartpointertest \
-	sllisttest iteratorfacadetest tuplestest fvectortest fmatrixtest \
+	sllisttest iteratorfacadetest iteratorfacadetest2 tuplestest fvectortest fmatrixtest \
 	poolallocatortest settest gcdlcmtest streamtest \
 	bigunsignedinttest mpihelpertest singletontest mpicollcomm \
 	utilitytest lrutest \
@@ -38,6 +38,8 @@ XFAIL_TESTS = testfassign_fail1 testfassign_fail2 testfassign_fail3 \
 # programs just to build when "make check" is used
 check_PROGRAMS = $(TESTPROGS)
 
+noinst_HEADERS = dummyiterator.hh
+
 AM_LDFLAGS = $(LOCAL_LIBS)
 
 # define the programs
@@ -75,6 +77,8 @@ streamtest_SOURCES = streamtest.cc
 iteratorfacadetest_SOURCES = iteratorfacadetest.cc iteratorfacadetest.hh \
    iteratortest.hh
 
+iteratorfacadetest2_SOURCES = iteratorfacadetest2.cc
+
 fvectortest_SOURCES = fvectortest.cc
 
 fmatrixtest_SOURCES = fmatrixtest.cc

dune/common/test/dummyiterator.hh

+// -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+// vi: set et ts=4 sw=2 sts=2:
+#ifndef DUNE_COMMON_DUMMYITERATOR_HH
+#define DUNE_COMMON_DUMMYITERATOR_HH
+
+#include <cstddef>
+
+#include <dune/common/iteratorfacades.hh>
+#include <dune/common/typetraits.hh>
+
+template<typename T>
+class dummyiterator
+  : public Dune::BidirectionalIteratorFacade<dummyiterator<T>, T, T&,
+        std::ptrdiff_t>
+{
+  friend class dummyiterator<const typename Dune::remove_const<T>::type>;
+
+  T *value;
+
+public:
+  dummyiterator(T& value_)
+    : value(&value_)
+  {}
+
+  template<typename T2>
+  dummyiterator
+    ( const dummyiterator<T2>& o,
+    typename Dune::enable_if<Dune::Conversion<T2&, T&>::exists>::type* = 0)
+    : value(o.value)
+  {}
+
+  T& derefence() const {
+    return *value;
+  }
+
+  bool equals(const dummyiterator& o) const {
+    return value == o.value;
+  }
+
+  void increment() {}
+  void decrement() {}
+};
+
+#endif // DUNE_COMMON_DUMMYITERATOR_HH

dune/common/test/iteratorfacadetest2.cc

+// -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+// vi: set et ts=4 sw=2 sts=2:
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "dummyiterator.hh"
+
+int main(){
+  // Check that iterator<T> can be compared with iterator<const T> as soon as
+  // a conversion from iterator<T> to iterator<const T> exists
+
+  int value = 0;
+  dummyiterator<int> mit(value);
+  dummyiterator<const int> cit(value);
+
+  bool result = mit == cit;
+
+  if(result) return 0;
+  else return 1;
+}