Milena (Olena)
User documentation 2.0a Id
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00001 // Copyright (C) 2007, 2008, 2009 EPITA Research and Development Laboratory (LRDE) 00002 // 00003 // This file is part of Olena. 00004 // 00005 // Olena is free software: you can redistribute it and/or modify it under 00006 // the terms of the GNU General Public License as published by the Free 00007 // Software Foundation, version 2 of the License. 00008 // 00009 // Olena is distributed in the hope that it will be useful, 00010 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00011 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00012 // General Public License for more details. 00013 // 00014 // You should have received a copy of the GNU General Public License 00015 // along with Olena. If not, see <http://www.gnu.org/licenses/>. 00016 // 00017 // As a special exception, you may use this file as part of a free 00018 // software project without restriction. Specifically, if other files 00019 // instantiate templates or use macros or inline functions from this 00020 // file, or you compile this file and link it with other files to produce 00021 // an executable, this file does not by itself cause the resulting 00022 // executable to be covered by the GNU General Public License. This 00023 // exception does not however invalidate any other reasons why the 00024 // executable file might be covered by the GNU General Public License. 00025 00026 #ifndef MLN_METAL_MATH_SQRT_HH 00027 # define MLN_METAL_MATH_SQRT_HH 00028 00036 # include <mln/metal/bool.hh> 00037 # include <mln/metal/int.hh> 00038 00039 00040 # define mlc_sqrt_int(N) mln::metal::math::sqrt_int<( N )>::value 00041 00042 00043 namespace mln 00044 { 00045 00046 namespace metal 00047 { 00048 00049 namespace math 00050 { 00051 00052 // sqrt_int<x> 00053 00054 namespace impl 00055 { 00056 00057 template <int n, int lo = 1, int hi = n> 00058 struct sqrt_int_ 00059 { 00060 enum { 00061 mid = (lo + hi + 1) / 2, 00062 val_lo = sqrt_int_<n, lo, mid-1>::value, 00063 val_hi = sqrt_int_<n, mid, hi>::value 00064 }; 00065 enum { value = n < mid * mid ? val_lo : val_hi }; 00066 }; 00067 00068 template<int n, int m> 00069 struct sqrt_int_<n, m, m> 00070 { 00071 enum { value = m }; 00072 }; 00073 00074 // Entry. 00075 00076 template <int n, bool b> 00077 struct sqrt_int_if_ : sqrt_int_<n> 00078 { 00079 enum { value_ = sqrt_int_<n>::value, 00080 reminder_ = n - value_ * value_ }; 00081 // FIXME: Check that reminder_ == 0. 00082 }; 00083 00084 template <int n> 00085 struct sqrt_int_if_< n, false > 00086 { 00087 }; 00088 00089 } // end of namespace mln::metal::math::impl 00090 00091 template <int n> 00092 struct sqrt_int : impl::sqrt_int_if_< n, (n >= 0) > 00093 { 00094 }; 00095 00096 00097 // sqrt<N> 00098 00099 template <typename N> 00100 struct sqrt; 00101 00102 template <int n> 00103 struct sqrt< int_<n> > 00104 { 00105 typedef int_< sqrt_int<n>::value > ret; 00106 }; 00107 00108 00109 } // end of namespace mln::metal::math 00110 00111 } // end of namespace mln::metal 00112 00113 } // end of namespace mln 00114 00115 00116 #endif // ! MLN_METAL_MATH_SQRT_HH