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+///\file
+
+/******************************************************************************
+The MIT License(MIT)
+
+Embedded Template Library.
+https://github.com/ETLCPP/etl
+http://www.etlcpp.com
+
+Copyright(c) 2014 jwellbelove
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files(the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and / or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions :
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+******************************************************************************/
+
+#ifndef __ETL_FACTORIAL__
+#define __ETL_FACTORIAL__
+
+#include <stddef.h>
+
+///\defgroup factorial factorial
+/// fibonacci<N> : Calculates the Nth factorial value.
+///\ingroup maths
+
+namespace etl 
+{
+  //***************************************************************************
+  ///\ingroup fibonacci
+  /// Defines <b>value</b> as the Nth factorial number.
+  ///\tparam N The number to find the factorial value of.
+  //***************************************************************************
+  template <size_t N>
+  struct factorial
+  {
+    static const size_t value = N * factorial<N - 1>::value;
+  };
+
+  //***************************************************************************
+  // Specialisation for N = 0
+  //***************************************************************************
+  template <>
+  struct factorial<0>
+  {
+    static const size_t value = 1;
+  };
+}
+
+#endif