From 4152f73fcda756d1243f5bb51b050aa9e20408d0 Mon Sep 17 00:00:00 2001
From: Oliver Sander <sander@igpm.rwth-aachen.de>
Date: Fri, 23 Aug 2013 10:25:33 +0200
Subject: [PATCH] Use variadic templates for PushBackTuple and PushFrontTuple,
if available
The two classes PushBackTuple and PushFrontTuple are both implemented
using a long list of template specializations. This makes for a lot
of code, and it also limits the maximum tuple size that can be used.
Using variadic templates (FYI: available since gcc-4.3) instead
allows a generic implementation in only a few lines of code, and
only the compiler being the upper limit on tuple size.
An implementation using variadic templates has already been given
in the documentation of PushBackTuple/PushFrontTuple. This patch
starts to actually use that implementation, provided that
HAVE_VARIADIC_TEMPLATES is set. Otherwise the old implementation
is used.
---
dune/common/tupleutility.hh | 38 ++++++++++++++++---------------------
1 file changed, 16 insertions(+), 22 deletions(-)
diff --git a/dune/common/tupleutility.hh b/dune/common/tupleutility.hh
index 9e2327fa2..9fd019de5 100644
--- a/dune/common/tupleutility.hh
+++ b/dune/common/tupleutility.hh
@@ -1572,17 +1572,6 @@ namespace Dune {
*
* \tparam Tuple The tuple type to extend
* \tparam T The type to be appended to the tuple
- *
- * With variadic templates the generic specialization would be:
- *
- * \code
- * template<class... TupleArgs, class T>
- * struct PushBackTuple<typename Dune::tuple<TupleArgs...>, T>
- * {
- * typedef typename Dune::tuple<TupleArgs..., T> type;
- * };
- * \endcode
- *
*/
template< class Tuple, class T>
struct PushBackTuple
@@ -1607,6 +1596,13 @@ namespace Dune {
#ifndef DOXYGEN
+#if HAVE_VARIADIC_TEMPLATES
+ template<class... TupleArgs, class T>
+ struct PushBackTuple<typename Dune::tuple<TupleArgs...>, T>
+ {
+ typedef typename Dune::tuple<TupleArgs..., T> type;
+ };
+#else
template<class T>
struct PushBackTuple< Dune::tuple<>, T>
{
@@ -1660,6 +1656,7 @@ namespace Dune {
{
typedef typename Dune::tuple<T1, T2, T3, T4, T5, T6, T7, T8, T> type;
};
+#endif // HAVE_VARIADIC_TEMPLATES
#endif
@@ -1670,17 +1667,6 @@ namespace Dune {
*
* \tparam Tuple The tuple type to extend
* \tparam T The type to be prepended to the tuple
- *
- * With variadic templates the generic specialization would be:
- *
- * \code
- * template<class... TupleArgs, class T>
- * struct PushFrontTuple<typename Dune::tuple<TupleArgs...>, T>
- * {
- * typedef typename Dune::tuple<T, TupleArgs...> type;
- * };
- * \endcode
- *
*/
template< class Tuple, class T>
struct PushFrontTuple
@@ -1705,6 +1691,13 @@ namespace Dune {
#ifndef DOXYGEN
+#if HAVE_VARIADIC_TEMPLATES
+ template<class... TupleArgs, class T>
+ struct PushFrontTuple<typename Dune::tuple<TupleArgs...>, T>
+ {
+ typedef typename Dune::tuple<T, TupleArgs...> type;
+ };
+#else
template<class T>
struct PushFrontTuple< Dune::tuple<>, T>
{
@@ -1758,6 +1751,7 @@ namespace Dune {
{
typedef typename Dune::tuple<T, T1, T2, T3, T4, T5, T6, T7, T8> type;
};
+#endif // HAVE_VARIADIC_TEMPLATES
#endif
--
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