From 2f272b99c600a192ad605583ef69553aec944aad Mon Sep 17 00:00:00 2001
From: Jorrit Fahlke <joe@dune-project.org>
Date: Fri, 28 May 2010 14:21:44 +0000
Subject: [PATCH] [typetraits.hh] Add implementation of integral_constant.
If there is an implementation available in std or std::tr1 we fall back to
that.
[[Imported from SVN: r6022]]
---
dune/common/typetraits.hh | 37 +++++++++++++++++++++++++++++++++++++
1 file changed, 37 insertions(+)
diff --git a/dune/common/typetraits.hh b/dune/common/typetraits.hh
index 1ca6af741..12ca20197 100644
--- a/dune/common/typetraits.hh
+++ b/dune/common/typetraits.hh
@@ -369,6 +369,43 @@ namespace Dune
{
typedef T2 Type;
};
+
+ ////////////////////////////////////////////////////////////////////////
+ //
+ // integral_constant (C++0x 20.7.3 "Helper classes")
+ //
+#if defined HAVE_TYPE_TRAITS
+ using std::integral_constant;
+ using std::true_type;
+ using std::false_type;
+#elif defined HAVE_TR1_TYPE_TRAITS
+ using std::tr1::integral_constant;
+ using std::tr1::true_type;
+ using std::tr1::false_type;
+#else
+ //! Generate a type for a given integral constant
+ /**
+ * \tparam T Type of the constant.
+ * \tparam v Value of the constant.
+ */
+ template <class T, T v>
+ struct integral_constant {
+ //! value this type was generated for
+ static const T value = v;
+ //! type of value
+ typedef T value_type;
+ //! type of this class itself
+ typedef integral_constant<T,v> type;
+ //! conversion to value_type/T
+ operator value_type() { return value; }
+ };
+
+ //! type for true
+ typedef integral_constant<bool, true> true_type;
+ //! type for false
+ typedef integral_constant<bool, false> false_type;
+#endif
+
/** @} */
}
#endif
--
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