dust3d/thirdparty/cgal/CGAL-5.1/include/CGAL/NewKernel_d/utils.h

197 lines
7.5 KiB
C++

// Copyright (c) 2014
// INRIA Saclay-Ile de France (France)
//
// This file is part of CGAL (www.cgal.org)
//
// $URL: https://github.com/CGAL/cgal/blob/v5.1/NewKernel_d/include/CGAL/NewKernel_d/utils.h $
// $Id: utils.h 0779373 2020-03-26T13:31:46+01:00 Sébastien Loriot
// SPDX-License-Identifier: LGPL-3.0-or-later OR LicenseRef-Commercial
//
// Author(s) : Marc Glisse
#ifndef CGAL_MARCUTILS
#define CGAL_MARCUTILS
#include <CGAL/config.h>
#if defined(BOOST_MSVC)
# pragma warning(push)
# pragma warning(disable:4003) // not enough actual parameters for macro 'BOOST_PP_EXPAND_I'
// https://lists.boost.org/boost-users/2014/11/83291.php
#endif
#include <type_traits>
#include <utility>
#include <boost/utility/enable_if.hpp>
#include <boost/preprocessor/repetition.hpp>
#include <CGAL/Rational_traits.h>
#include <CGAL/tuple.h>
#include <boost/mpl/has_xxx.hpp>
#include <boost/mpl/not.hpp>
#include <boost/type_traits.hpp>
namespace CGAL {
namespace internal {
BOOST_MPL_HAS_XXX_TRAIT_DEF(type)
}
template <class T, class No, bool=internal::has_type<T>::value /*false*/>
struct Has_type_different_from : boost::false_type {};
template <class T, class No>
struct Has_type_different_from <T, No, true>
: boost::mpl::not_<boost::is_same<typename T::type, No> > {};
template <class T> struct Wrap_type { typedef T type; };
// tell a function f(a,b,c) that its real argument is a(b,c)
struct Eval_functor {};
// forget the first argument. Useful to make something dependant
// (and thus usable in SFINAE), although that's not a great design.
template<class A,class B> struct Second_arg {
typedef B type;
};
// like std::forward, except for basic types where it does a cast, to
// avoid issues with narrowing conversions
template<class T,class U,class V> inline
typename std::conditional<std::is_arithmetic<T>::value&&std::is_arithmetic<typename std::remove_reference<U>::type>::value,T,U&&>::type
forward_safe(V&& u) { return std::forward<U>(u); }
template<class...> struct Constructible_from_each;
template<class To,class From1,class...From> struct Constructible_from_each<To,From1,From...>{
enum { value=std::is_convertible<From1,To>::value&&Constructible_from_each<To,From...>::value };
};
template<class To> struct Constructible_from_each<To>{
enum { value=true };
};
template<class T> struct Scale {
T const& scale;
Scale(T const& t):scale(t){}
template<class FT>
decltype(auto) operator()(FT&& x)const
{
return (scale*std::forward<FT>(x));
}
};
template<class NT,class T> struct Divide {
T const& scale;
Divide(T const& t):scale(t){}
template<class FT>
//FIXME: gcc complains for Gmpq
//decltype(auto) operator()(FT&& x)const
NT operator()(FT&& x)const
{
return Rational_traits<NT>().
make_rational(std::forward<FT>(x),scale);
}
};
template <class NT> struct has_cheap_constructor : boost::is_arithmetic<NT>{};
template <bool p> struct has_cheap_constructor<Interval_nt<p> > {
enum { value=true };
};
// like std::multiplies but allows mixing types
// in C++11 in doesn't need to be a template
template < class Ret >
struct multiplies {
template<class A,class B>
decltype(auto) operator()(A&&a,B&&b)const
{
return std::forward<A>(a)*std::forward<B>(b);
}
};
template < class Ret >
struct division {
template<class A,class B>
decltype(auto) operator()(A&&a,B&&b)const
{
return std::forward<A>(a)/std::forward<B>(b);
}
};
using std::decay;
template<class T,class U> struct Type_copy_ref { typedef U type; };
template<class T,class U> struct Type_copy_ref<T&,U> { typedef U& type; };
template<class T,class U> struct Type_copy_ref<T&&,U> { typedef U&& type; };
template<class T,class U> struct Type_copy_cv { typedef U type; };
template<class T,class U> struct Type_copy_cv<T const,U> { typedef U const type; };
template<class T,class U> struct Type_copy_cv<T volatile,U> { typedef U volatile type; };
template<class T,class U> struct Type_copy_cv<T const volatile,U> { typedef U const volatile type; };
template<class T,class U> struct Type_copy_cvref :
Type_copy_ref<T,typename Type_copy_cv<typename boost::remove_reference<T>::type,U>::type> {};
struct Dereference_functor {
template<class> struct result{};
template<class It> struct result<Dereference_functor(It)> {
typedef typename std::iterator_traits<It>::reference type;
};
template<class It> decltype(auto)
operator()(It const&i)const{
return *i;
}
};
namespace internal {
template<class F,class...U,std::size_t...I> inline decltype(auto)
do_call_on_tuple_elements(F&&f, std::tuple<U...>&&t, std::index_sequence<I...>&&) {
return f(std::get<I>(std::move(t))...);
}
} // internal
template<class F,class...U>
inline decltype(auto)
call_on_tuple_elements(F&&f, std::tuple<U...>&&t) {
return internal::do_call_on_tuple_elements(std::forward<F>(f),std::move(t),
std::make_index_sequence<sizeof...(U)>());
}
template<class A> struct Factory {
typedef A result_type;
template<class...U> result_type operator()(U&&...u)const{
return A(std::forward<U>(u)...);
}
};
}
// TODO: make a Cartesian-only variant
// WARNING: do not use the Req* parameters too much, they can cause circular instanciations and are only useful for dispatching.
#define CGAL_STRIP_PAREN_(...) __VA_ARGS__
#define CGAL_STRIP_PAREN(...) CGAL_STRIP_PAREN_ __VA_ARGS__
// What to do with O? pass it down to other functors or drop it?
#define CGAL_KD_DEFAULT_FUNCTOR(Tg,Name,ReqTyp,ReqFun) \
template <class K, class O> \
struct Get_functor<K, Tg, O, \
typename boost::mpl::if_c< \
Provides_functor_i<K, Tg, O>::value \
|| !Provides_types<K, boost::mpl::vector<CGAL_STRIP_PAREN_ ReqTyp> >::value \
|| !Provides_functors<K, boost::mpl::vector<CGAL_STRIP_PAREN_ ReqFun> >::value \
, int, void>::type> \
{ \
typedef CGAL_STRIP_PAREN_ Name type; \
typedef K Bound_kernel; \
}
// Not used yet, may need some changes.
#define CGAL_KD_DEFAULT_TYPE(Tg,Name,ReqTyp,ReqFun) \
template <class K> \
struct Get_type<K, Tg, \
typename boost::mpl::if_c< \
Provides_type_i<K, Tg>::value \
|| !Provides_types<K, boost::mpl::vector<CGAL_STRIP_PAREN_ ReqTyp> >::value \
|| !Provides_functors<K, boost::mpl::vector<CGAL_STRIP_PAREN_ ReqFun> >::value \
, int, void>::type> \
{ \
typedef CGAL_STRIP_PAREN_ Name type; \
typedef K Bound_kernel; \
}
#if defined(BOOST_MSVC)
# pragma warning(pop)
#endif
#endif