1 files changed, 75 insertions, 0 deletions
diff --git a/Eigen/src/Eigen2Support/Meta.h b/Eigen/src/Eigen2Support/Meta.h
new file mode 100644
index 000000000..fa37cfc96
--- /dev/null
+++ b/Eigen/src/Eigen2Support/Meta.h
@@ -0,0 +1,75 @@
+// This file is part of Eigen, a lightweight C++ template library
+// for linear algebra.
+//
+// Copyright (C) 2011 Benoit Jacob <jacob.benoit.1@gmail.com>
+//
+// This Source Code Form is subject to the terms of the Mozilla
+// Public License v. 2.0. If a copy of the MPL was not distributed
+// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+#ifndef EIGEN2_META_H
+#define EIGEN2_META_H
+
+namespace Eigen { 
+
+template<typename T>
+struct ei_traits : internal::traits<T>
+{};
+
+struct ei_meta_true {  enum { ret = 1 }; };
+struct ei_meta_false { enum { ret = 0 }; };
+
+template<bool Condition, typename Then, typename Else>
+struct ei_meta_if { typedef Then ret; };
+
+template<typename Then, typename Else>
+struct ei_meta_if <false, Then, Else> { typedef Else ret; };
+
+template<typename T, typename U> struct ei_is_same_type { enum { ret = 0 }; };
+template<typename T> struct ei_is_same_type<T,T> { enum { ret = 1 }; };
+
+template<typename T> struct ei_unref { typedef T type; };
+template<typename T> struct ei_unref<T&> { typedef T type; };
+
+template<typename T> struct ei_unpointer { typedef T type; };
+template<typename T> struct ei_unpointer<T*> { typedef T type; };
+template<typename T> struct ei_unpointer<T*const> { typedef T type; };
+
+template<typename T> struct ei_unconst { typedef T type; };
+template<typename T> struct ei_unconst<const T> { typedef T type; };
+template<typename T> struct ei_unconst<T const &> { typedef T & type; };
+template<typename T> struct ei_unconst<T const *> { typedef T * type; };
+
+template<typename T> struct ei_cleantype { typedef T type; };
+template<typename T> struct ei_cleantype<const T>   { typedef typename ei_cleantype<T>::type type; };
+template<typename T> struct ei_cleantype<const T&>  { typedef typename ei_cleantype<T>::type type; };
+template<typename T> struct ei_cleantype<T&>        { typedef typename ei_cleantype<T>::type type; };
+template<typename T> struct ei_cleantype<const T*>  { typedef typename ei_cleantype<T>::type type; };
+template<typename T> struct ei_cleantype<T*>        { typedef typename ei_cleantype<T>::type type; };
+
+/** \internal In short, it computes int(sqrt(\a Y)) with \a Y an integer.
+  * Usage example: \code ei_meta_sqrt<1023>::ret \endcode
+  */
+template<int Y,
+         int InfX = 0,
+         int SupX = ((Y==1) ? 1 : Y/2),
+         bool Done = ((SupX-InfX)<=1 ? true : ((SupX*SupX <= Y) && ((SupX+1)*(SupX+1) > Y))) >
+                                // use ?: instead of || just to shut up a stupid gcc 4.3 warning
+class ei_meta_sqrt
+{
+    enum {
+      MidX = (InfX+SupX)/2,
+      TakeInf = MidX*MidX > Y ? 1 : 0,
+      NewInf = int(TakeInf) ? InfX : int(MidX),
+      NewSup = int(TakeInf) ? int(MidX) : SupX
+    };
+  public:
+    enum { ret = ei_meta_sqrt<Y,NewInf,NewSup>::ret };
+};
+
+template<int Y, int InfX, int SupX>
+class ei_meta_sqrt<Y, InfX, SupX, true> { public:  enum { ret = (SupX*SupX <= Y) ? SupX : InfX }; };
+
+} // end namespace Eigen
+
+#endif // EIGEN2_META_H