// Boost.Geometry
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// Copyright (c) 2020, Oracle and/or its affiliates.
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// Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
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// Licensed under the Boost Software License version 1.0.
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// http://www.boost.org/users/license.html
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#ifndef BOOST_GEOMETRY_UTIL_TYPE_TRAITS_STD_HPP
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#define BOOST_GEOMETRY_UTIL_TYPE_TRAITS_STD_HPP
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#include <cstddef>
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#include <type_traits>
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namespace boost { namespace geometry
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{
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namespace util
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{
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// C++17
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template <bool B>
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using bool_constant = std::integral_constant<bool, B>;
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// non-standard
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template <int I>
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using int_constant = std::integral_constant<int, I>;
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// non-standard
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template <std::size_t I>
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using index_constant = std::integral_constant<std::size_t, I>;
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// non-standard
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template <std::size_t S>
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using size_constant = std::integral_constant<std::size_t, S>;
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// C++17
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template <typename ...>
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struct conjunction
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: std::true_type
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{};
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template<typename Trait>
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struct conjunction<Trait>
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: Trait
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{};
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template <typename Trait, typename ...Traits>
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struct conjunction<Trait, Traits...>
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: std::conditional_t<Trait::value, conjunction<Traits...>, Trait>
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{};
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// C++17
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template <typename ...>
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struct disjunction
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: std::false_type
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{};
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template <typename Trait>
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struct disjunction<Trait>
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: Trait
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{};
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template <typename Trait, typename ...Traits>
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struct disjunction<Trait, Traits...>
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: std::conditional_t<Trait::value, Trait, disjunction<Traits...>>
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{};
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// C++17
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template <typename Trait>
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struct negation
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: bool_constant<!Trait::value>
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{};
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// non-standard
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/*
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template <typename ...Traits>
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using and_ = conjunction<Traits...>;
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template <typename ...Traits>
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using or_ = disjunction<Traits...>;
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template <typename Trait>
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using not_ = negation<Trait>;
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*/
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// C++20
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template <typename T>
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struct remove_cvref
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{
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using type = std::remove_cv_t<std::remove_reference_t<T>>;
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};
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template <typename T>
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using remove_cvref_t = typename remove_cvref<T>::type;
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// non-standard
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template <typename T>
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struct remove_cref
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{
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using type = std::remove_const_t<std::remove_reference_t<T>>;
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};
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template <typename T>
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using remove_cref_t = typename remove_cref<T>::type;
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// non-standard
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template <typename T>
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struct remove_cptrref
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{
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using type = std::remove_const_t
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<
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std::remove_pointer_t<std::remove_reference_t<T>>
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>;
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};
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template <typename T>
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using remove_cptrref_t = typename remove_cptrref<T>::type;
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// non-standard
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template <typename From, typename To>
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struct transcribe_const
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{
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using type = std::conditional_t
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<
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std::is_const<std::remove_reference_t<From>>::value,
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std::add_const_t<To>,
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To
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>;
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};
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template <typename From, typename To>
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using transcribe_const_t = typename transcribe_const<From, To>::type;
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} // namespace util
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// Deprecated utilities, defined for backward compatibility but might be
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// removed in the future.
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/*!
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\brief Meta-function to define a const or non const type
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\ingroup utility
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\details If the boolean template parameter is true, the type parameter
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will be defined as const, otherwise it will be defined as it was.
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This meta-function is used to have one implementation for both
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const and non const references
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\note This traits class is completely independant from Boost.Geometry
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and might be a separate addition to Boost
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\note Used in a.o. for_each, interior_rings, exterior_ring
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\par Example
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\code
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void foo(typename add_const_if_c<IsConst, Point>::type& point)
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\endcode
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*/
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template <bool IsConst, typename Type>
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struct add_const_if_c
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{
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typedef std::conditional_t
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<
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IsConst,
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Type const,
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Type
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> type;
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};
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namespace util
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{
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template <typename T>
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using bare_type = remove_cptrref<T>;
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} // namespace util
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}} // namespace boost::geometry
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#endif // BOOST_GEOMETRY_UTIL_TYPE_TRAITS_STD_HPP
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