From 017394e17f35647fd5656e6cc783f2d643fcdb3e Mon Sep 17 00:00:00 2001
From: Olivier Parcollet <olivier.parcollet@cea.fr>
Date: Wed, 21 Aug 2013 17:25:45 +0200
Subject: [PATCH] arrays : add experimental array_const_view

- not completely clear how to
manipulate this alias, in particular when
matching template function
(and portability : require C++11 compiler).
---
 test/triqs/arrays/alias_const_view.cpp | 47 ++++++++++++++++++++++++++
 triqs/arrays/array.hpp                 |  7 ++++
 2 files changed, 54 insertions(+)
 create mode 100644 test/triqs/arrays/alias_const_view.cpp

diff --git a/test/triqs/arrays/alias_const_view.cpp b/test/triqs/arrays/alias_const_view.cpp
new file mode 100644
index 00000000..343e5303
--- /dev/null
+++ b/test/triqs/arrays/alias_const_view.cpp
@@ -0,0 +1,47 @@
+/*******************************************************************************
+ *
+ * TRIQS: a Toolbox for Research in Interacting Quantum Systems
+ *
+ * Copyright (C) 2013 by O. Parcollet
+ *
+ * TRIQS is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later
+ * version.
+ *
+ * TRIQS is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * TRIQS. If not, see <http://www.gnu.org/licenses/>.
+ *
+ ******************************************************************************/
+
+#include "./common.hpp"
+#include "./src/array.hpp"
+#include <iostream>
+
+//using std::cout; using std::endl;
+using namespace triqs::arrays;
+#include <type_traits>
+
+
+template<typename U, ull_t opt, ull_t to, bool B> 
+void f (array_const_view<U,2,opt,to,B> const & a) { 
+ std::cout  << a << std::endl ;
+}
+
+int main(int argc, char **argv) {
+
+ array<long,2 > A (2,3);
+ A() =3;
+
+ f(A());
+
+}
+
+
+
+
diff --git a/triqs/arrays/array.hpp b/triqs/arrays/array.hpp
index 2791be27..c0625fb1 100644
--- a/triqs/arrays/array.hpp
+++ b/triqs/arrays/array.hpp
@@ -86,6 +86,13 @@ namespace triqs { namespace arrays {
   };
 
 #undef IMPL_TYPE
+
+// This alias is experiemental !! on modern compilers only.
+#ifndef TRIQS_COMPILER_IS_OBSOLETE
+ template <typename ValueType, int Rank, ull_t Opt=0, ull_t TraversalOrder=0, bool Borrowed=false>
+ using array_const_view = array_view<ValueType, Rank, Opt, TraversalOrder, Borrowed>; 
+#endif
+
  //------------------------------- array ---------------------------------------------------
 
 #define IMPL_TYPE indexmap_storage_pair< indexmaps::cuboid::map<Rank,Opt,TraversalOrder>, \