From: steven_at_[hidden]
Date: 2008-02-25 17:48:07
Author: steven_watanabe
Date: 2008-02-25 17:48:07 EST (Mon, 25 Feb 2008)
New Revision: 43415
URL: http://svn.boost.org/trac/boost/changeset/43415
Log:
Optimized be replacing fold with a custom loop
Text files modified:
sandbox/switch/libs/switch/alternate/switch/case.hpp | 18 ++++++++++++++----
1 files changed, 14 insertions(+), 4 deletions(-)
Modified: sandbox/switch/libs/switch/alternate/switch/case.hpp
==============================================================================
--- sandbox/switch/libs/switch/alternate/switch/case.hpp (original)
+++ sandbox/switch/libs/switch/alternate/switch/case.hpp 2008-02-25 17:48:07 EST (Mon, 25 Feb 2008)
@@ -12,7 +12,6 @@
#include <boost/utility/enable_if.hpp>
#include <boost/mpl/int.hpp>
-#include <boost/mpl/fold.hpp>
#include <boost/mpl/joint_view.hpp>
#include <boost/mpl/single_view.hpp>
#include <boost/mpl/range_c.hpp>
@@ -33,14 +32,25 @@
typedef set type;
};
-template<class S>
+template<int N>
struct make_set {
- typedef typename mpl::fold<S, empty_set, set<mpl::_, mpl::_> >::type type;
+ template<class Iter>
+ struct apply {
+ typedef set<typename make_set<N - 1>::template apply<typename boost::mpl::next<Iter>::type>::type, typename boost::mpl::deref<Iter>::type> type;
+ };
+};
+
+template<>
+struct make_set<0> {
+ template<class Iter>
+ struct apply {
+ typedef empty_set type;
+ };
};
template<class S, class N>
struct contains_impl {
- typedef typename switch_detail::make_set<S>::type as_set;
+ typedef typename make_set<boost::mpl::size<S>::value>::template apply<typename boost::mpl::begin<S>::type>::type as_set;
static const bool value = (sizeof(as_set::lookup(N())) != 1);
};