108 lines
4.2 KiB
C++
108 lines
4.2 KiB
C++
/* boost random/traits.hpp header file
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*
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* Copyright John Maddock 2015
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* Distributed under the Boost Software License, Version 1.0. (See
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* accompanying file LICENSE_1_0.txt or copy at
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* http://www.boost.org/LICENSE_1_0.txt)
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*
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* See http://www.boost.org for most recent version including documentation.
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*
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* These traits classes serve two purposes: they are designed to mostly
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* work out of the box for multiprecision types (ie number types that are
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* C++ class types and not integers or floats from type-traits point of view),
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* they are also a potential point of specialization for user-defined
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* number types.
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*
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* $Id$
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*/
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#ifndef BOOST_RANDOM_TRAITS_HPP
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#define BOOST_RANDOM_TRAITS_HPP
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#include <boost/type_traits/is_signed.hpp>
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#include <boost/type_traits/is_integral.hpp>
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#include <boost/type_traits/make_unsigned.hpp>
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#include <boost/mpl/bool.hpp>
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#include <limits>
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namespace boost {
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namespace random {
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namespace traits {
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// \cond show_private
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template <class T, bool intrinsic>
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struct make_unsigned_imp
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{
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typedef typename boost::make_unsigned<T>::type type;
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};
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template <class T>
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struct make_unsigned_imp<T, false>
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{
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BOOST_STATIC_ASSERT(std::numeric_limits<T>::is_specialized);
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BOOST_STATIC_ASSERT(std::numeric_limits<T>::is_signed == false);
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BOOST_STATIC_ASSERT(std::numeric_limits<T>::is_integer == true);
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typedef T type;
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};
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// \endcond
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/** \brief Converts the argument type T to an unsigned type.
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*
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* This trait has a single member `type` which is the unsigned type corresponding to T.
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* Note that
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* if T is signed, then member `type` *should define a type with one more bit precision than T*. For built-in
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* types this trait defaults to `boost::make_unsigned<T>::type`. For user defined types it simply asserts that
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* the argument type T is an unsigned integer (using std::numeric_limits).
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* User defined specializations may be provided for other cases.
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*/
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template <class T>
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struct make_unsigned
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// \cond show_private
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: public make_unsigned_imp < T, boost::is_integral<T>::value >
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// \endcond
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{};
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// \cond show_private
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template <class T, bool intrinsic>
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struct make_unsigned_or_unbounded_imp
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{
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typedef typename boost::make_unsigned<T>::type type;
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};
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template <class T>
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struct make_unsigned_or_unbounded_imp<T, false>
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{
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BOOST_STATIC_ASSERT(std::numeric_limits<T>::is_specialized);
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BOOST_STATIC_ASSERT((std::numeric_limits<T>::is_signed == false) || (std::numeric_limits<T>::is_bounded == false));
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BOOST_STATIC_ASSERT(std::numeric_limits<T>::is_integer == true);
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typedef T type;
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};
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// \endcond
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/** \brief Converts the argument type T to either an unsigned type or an unbounded integer type.
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*
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* This trait has a single member `type` which is either the unsigned type corresponding to T or an unbounded
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* integer type. This trait is used to generate types suitable for the calculation of a range: as a result
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* if T is signed, then member `type` *should define a type with one more bit precision than T*. For built-in
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* types this trait defaults to `boost::make_unsigned<T>::type`. For user defined types it simply asserts that
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* the argument type T is either an unbounded integer, or an unsigned one (using std::numeric_limits).
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* User defined specializations may be provided for other cases.
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*/
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template <class T>
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struct make_unsigned_or_unbounded
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// \cond show_private
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: public make_unsigned_or_unbounded_imp < T, boost::is_integral<T>::value >
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// \endcond
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{};
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/** \brief Traits class that indicates whether type T is an integer
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*/
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template <class T>
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struct is_integral
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: public mpl::bool_<boost::is_integral<T>::value || (std::numeric_limits<T>::is_integer)>
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{};
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/** \brief Traits class that indicates whether type T is a signed integer
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*/
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template <class T> struct is_signed
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: public mpl::bool_ < boost::is_signed<T>::value || (std::numeric_limits<T>::is_specialized && std::numeric_limits<T>::is_integer && std::numeric_limits<T>::is_signed)>
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{};
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}
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}
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}
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#endif
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