ClickHouse/contrib/libboost/boost_1_62_0/boost/random/traits.hpp

108 lines
4.1 KiB
C++
Raw Normal View History

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