From b55ae85e11ab4f06542fa55a72c5ff07fa0995e7 Mon Sep 17 00:00:00 2001
From: Pascal Germroth <pascal@ensieve.org>
Date: Mon, 5 Aug 2013 23:31:33 +0200
Subject: [PATCH] Use Range in openmp_nested_algebra. #6

---
 .../external/openmp/openmp_nested_algebra.hpp | 28 ++++++++++++-------
 1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/boost/numeric/odeint/external/openmp/openmp_nested_algebra.hpp b/boost/numeric/odeint/external/openmp/openmp_nested_algebra.hpp
index 57de3ef7..4d0520c5 100644
--- a/boost/numeric/odeint/external/openmp/openmp_nested_algebra.hpp
+++ b/boost/numeric/odeint/external/openmp/openmp_nested_algebra.hpp
@@ -18,6 +18,8 @@
 #ifndef BOOST_NUMERIC_ODEINT_EXTERNAL_OPENMP_OPENMP_NESTED_ALGEBRA_HPP_INCLUDED
 #define BOOST_NUMERIC_ODEINT_EXTERNAL_OPENMP_OPENMP_NESTED_ALGEBRA_HPP_INCLUDED
 
+#include <boost/assert.hpp>
+#include <boost/range.hpp>
 #include <boost/numeric/odeint/algebra/norm_result_type.hpp>
 #include <boost/numeric/odeint/util/n_ary_helper.hpp>
 
@@ -26,38 +28,44 @@ namespace numeric {
 namespace odeint {
 
 /** \brief OpenMP-parallelized algebra, wrapping another, non-parallelized algebra.
- * The NestedState must be a Random Access Container where the elements are sub-states
- * which will be processed in parallel.
  *
- * Requires a NestedState with `s::value_type`, `s[n]` and `s.size()`.
+ * NestedState must be a model of Random Access Range, where the elements are sub-states
+ * which will be processed in parallel.
  */
 template< class InnerAlgebra >
 struct openmp_nested_algebra
 {
 
 // FIXME: _Pragma is C++11.
+#define BOOST_ODEINT_GEN_LOCAL(z, n, unused) \
+    BOOST_ASSERT_MSG( len == boost::size(s ## n), "All nested state ranges must have the same size." ); \
+    typename boost::range_iterator<S ## n>::type beg ## n = boost::begin(s ## n);
 #define BOOST_ODEINT_GEN_BODY(n) \
-    const size_t len = s0.size(); \
+    const size_t len = boost::size(s0); \
+    BOOST_PP_REPEAT(n, BOOST_ODEINT_GEN_LOCAL, ~) \
     _Pragma("omp parallel for schedule(runtime)") \
     for( size_t i = 0 ; i < len ; i++ ) \
         InnerAlgebra::for_each##n( \
-            BOOST_PP_ENUM_BINARY_PARAMS(n, s, [i] BOOST_PP_INTERCEPT) , \
+            BOOST_PP_ENUM_BINARY_PARAMS(n, beg, [i] BOOST_PP_INTERCEPT) , \
             op \
         );
 BOOST_ODEINT_GEN_FOR_EACH(BOOST_ODEINT_GEN_BODY)
 #undef BOOST_ODEINT_GEN_BODY
+#undef BOOST_ODEINT_GEN_LOCAL
 
 
     template< class NestedState >
     static typename norm_result_type< typename NestedState::value_type >::type norm_inf( const NestedState &s )
     {
-        using std::max;
-        using std::abs;
-        typedef typename norm_result_type< typename NestedState::value_type >::type result_type;
+        typedef typename boost::range_iterator<const NestedState>::type iterator;
+        typedef typename std::iterator_traits<iterator>::value_type value_type;
+        typedef typename norm_result_type<value_type>::type result_type;
         result_type init = static_cast< result_type >( 0 );
+        const size_t len = boost::size(s);
+        iterator beg = boost::begin(s);
 #       pragma omp parallel for reduction(max: init) schedule(dynamic)
-        for( size_t i = 0 ; i < s.size() ; i++ )
-            init = max( init , InnerAlgebra::norm_inf( s[i] ) );
+        for( size_t i = 0 ; i < len ; i++ )
+            init = (std::max)( init , InnerAlgebra::norm_inf( beg[i] ) );
         return init;
     }