1 | // This file is part of Eigen, a lightweight C++ template library
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2 | // for linear algebra.
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3 | //
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4 | // Copyright (C) 2011 Benoit Jacob <jacob.benoit.1@gmail.com>
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5 | //
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6 | // This Source Code Form is subject to the terms of the Mozilla
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7 | // Public License v. 2.0. If a copy of the MPL was not distributed
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8 | // with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
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9 |
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10 | #ifndef EIGEN2_META_H
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11 | #define EIGEN2_META_H
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12 |
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13 | namespace Eigen {
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14 |
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15 | template<typename T>
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16 | struct ei_traits : internal::traits<T>
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17 | {};
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18 |
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19 | struct ei_meta_true { enum { ret = 1 }; };
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20 | struct ei_meta_false { enum { ret = 0 }; };
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21 |
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22 | template<bool Condition, typename Then, typename Else>
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23 | struct ei_meta_if { typedef Then ret; };
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24 |
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25 | template<typename Then, typename Else>
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26 | struct ei_meta_if <false, Then, Else> { typedef Else ret; };
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27 |
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28 | template<typename T, typename U> struct ei_is_same_type { enum { ret = 0 }; };
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29 | template<typename T> struct ei_is_same_type<T,T> { enum { ret = 1 }; };
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30 |
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31 | template<typename T> struct ei_unref { typedef T type; };
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32 | template<typename T> struct ei_unref<T&> { typedef T type; };
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33 |
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34 | template<typename T> struct ei_unpointer { typedef T type; };
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35 | template<typename T> struct ei_unpointer<T*> { typedef T type; };
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36 | template<typename T> struct ei_unpointer<T*const> { typedef T type; };
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37 |
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38 | template<typename T> struct ei_unconst { typedef T type; };
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39 | template<typename T> struct ei_unconst<const T> { typedef T type; };
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40 | template<typename T> struct ei_unconst<T const &> { typedef T & type; };
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41 | template<typename T> struct ei_unconst<T const *> { typedef T * type; };
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42 |
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43 | template<typename T> struct ei_cleantype { typedef T type; };
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44 | template<typename T> struct ei_cleantype<const T> { typedef typename ei_cleantype<T>::type type; };
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45 | template<typename T> struct ei_cleantype<const T&> { typedef typename ei_cleantype<T>::type type; };
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46 | template<typename T> struct ei_cleantype<T&> { typedef typename ei_cleantype<T>::type type; };
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47 | template<typename T> struct ei_cleantype<const T*> { typedef typename ei_cleantype<T>::type type; };
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48 | template<typename T> struct ei_cleantype<T*> { typedef typename ei_cleantype<T>::type type; };
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49 |
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50 | /** \internal In short, it computes int(sqrt(\a Y)) with \a Y an integer.
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51 | * Usage example: \code ei_meta_sqrt<1023>::ret \endcode
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52 | */
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53 | template<int Y,
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54 | int InfX = 0,
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55 | int SupX = ((Y==1) ? 1 : Y/2),
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56 | bool Done = ((SupX-InfX)<=1 ? true : ((SupX*SupX <= Y) && ((SupX+1)*(SupX+1) > Y))) >
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57 | // use ?: instead of || just to shut up a stupid gcc 4.3 warning
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58 | class ei_meta_sqrt
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59 | {
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60 | enum {
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61 | MidX = (InfX+SupX)/2,
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62 | TakeInf = MidX*MidX > Y ? 1 : 0,
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63 | NewInf = int(TakeInf) ? InfX : int(MidX),
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64 | NewSup = int(TakeInf) ? int(MidX) : SupX
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65 | };
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66 | public:
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67 | enum { ret = ei_meta_sqrt<Y,NewInf,NewSup>::ret };
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68 | };
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69 |
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70 | template<int Y, int InfX, int SupX>
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71 | class ei_meta_sqrt<Y, InfX, SupX, true> { public: enum { ret = (SupX*SupX <= Y) ? SupX : InfX }; };
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72 |
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73 | } // end namespace Eigen
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74 |
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75 | #endif // EIGEN2_META_H
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