[Olena-patches] proto-1.0 63: Add power of 2 traits in metalic

Index: ChangeLog from Damien Thivolle &lt;damien(a)lrde.epita.fr&gt; * mlc/math.hh: Add power of 2 traits. * mlc/makefile.src: Add new file. makefile.src | 1 math.hh | 82 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 83 insertions(+) Index: mlc/math.hh --- mlc/math.hh (revision 0) +++ mlc/math.hh (revision 0) @@ -0,0 +1,82 @@ +// Copyright (C) 2001, 2002, 2003 EPITA Research and Development Laboratory +// +// This file is part of the Olena Library. This library is free +// software; you can redistribute it and/or modify it under the terms +// of the GNU General Public License version 2 as published by the +// Free Software Foundation. +// +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +// General Public License for more details. +// +// You should have received a copy of the GNU General Public License +// along with this library; see the file COPYING. If not, write to +// the Free Software Foundation, 59 Temple Place - Suite 330, Boston, +// MA 02111-1307, USA. +// +// As a special exception, you may use this file as part of a free +// software library without restriction. Specifically, if other files +// instantiate templates or use macros or inline functions from this +// file, or you compile this file and link it with other files to +// produce an executable, this file does not by itself cause the +// resulting executable to be covered by the GNU General Public +// License. This exception does not however invalidate any other +// reasons why the executable file might be covered by the GNU General +// Public License. + +#ifndef METALIC_MATH_HH +# define METALIC_MATH_HH + +# include <mlc/bool.hh> + +namespace mlc +{ + + namespace internal + { + + // Helper structs for pow2sup below. + + template<unsigned N> struct is_pow2 { typedef false_type ret; }; + template<> struct is_pow2<8> { typedef true_type ret; }; + template<> struct is_pow2<16> { typedef true_type ret; }; + template<> struct is_pow2<32> { typedef true_type ret; }; + template<> struct is_pow2<64> { typedef true_type ret; }; + + template<unsigned N, class> struct find_pow2sup; + template<unsigned N> struct find_pow2sup<N,true_type> { + enum { value = N }; + }; + template<unsigned N> struct find_pow2sup<N,false_type> { + enum { value = find_pow2sup< N+1, + typename is_pow2<N+1>::ret >::value }; + }; + + } // end of internal + + // Smaller power of 2 greater than N. + + template<unsigned N> + struct pow2sup { + enum { + value = + internal::find_pow2sup< N, + typename internal::is_pow2<N>::ret >::value + }; + private: + typedef typename is_true<N < 32>::ensure_type precondition_type; + }; + + // Various tests on N (actually, we tests only oddness.) + + template<unsigned N> + class utest { + public: + typedef typename is_true<N/2 == (N+1)/2>::ensure_type is_odd_type; + static void ensure_odd() { is_odd_type::is_true(); } + }; + +} // end of namespace mlc + +#endif // METALIC_MATH_HH Index: mlc/makefile.src --- mlc/makefile.src (revision 62) +++ mlc/makefile.src (working copy) @@ -20,6 +20,7 @@ config/system.hh \ contract.hh \ is_a.hh \ + math.hh \ properties.hh \ tracked_ptr.hh \ traits.hh \