Added thirdparty: boost library

thirdparty/include/boost/math/tools/traits.hpp

@@ -0,0 +1,140 @@
+//  Copyright John Maddock 2007.
+//  Copyright Matt Borland 2021.
+//  Use, modification and distribution are subject to 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)
+
+/*
+This header defines two traits classes, both in namespace boost::math::tools.
+
+is_distribution<D>::value is true iff D has overloaded "cdf" and
+"quantile" functions, plus member typedefs value_type and policy_type.  
+It's not much of a definitive test frankly,
+but if it looks like a distribution and quacks like a distribution
+then it must be a distribution.
+
+is_scaled_distribution<D>::value is true iff D is a distribution
+as defined above, and has member functions "scale" and "location".
+
+*/
+
+#ifndef BOOST_STATS_IS_DISTRIBUTION_HPP
+#define BOOST_STATS_IS_DISTRIBUTION_HPP
+
+#ifdef _MSC_VER
+#pragma once
+#endif
+
+#include <type_traits>
+
+namespace boost{ namespace math{ namespace tools{
+
+namespace detail{
+
+#define BOOST_MATH_HAS_NAMED_TRAIT(trait, name)                         \
+template <typename T>                                                   \
+class trait                                                             \
+{                                                                       \
+private:                                                                \
+   using yes = char;                                                    \
+   struct no { char x[2]; };                                            \
+                                                                        \
+   template <typename U>                                                \
+   static yes test(typename U::name* = nullptr);                        \
+                                                                        \
+   template <typename U>                                                \
+   static no test(...);                                                 \
+                                                                        \
+public:                                                                 \
+   static constexpr bool value = (sizeof(test<T>(0)) == sizeof(char));  \
+};
+
+BOOST_MATH_HAS_NAMED_TRAIT(has_value_type, value_type)
+BOOST_MATH_HAS_NAMED_TRAIT(has_policy_type, policy_type)
+BOOST_MATH_HAS_NAMED_TRAIT(has_backend_type, backend_type)
+
+// C++17-esque helpers
+#if defined(__cpp_variable_templates) && __cpp_variable_templates >= 201304L
+template <typename T>
+constexpr bool has_value_type_v = has_value_type<T>::value;
+
+template <typename T>
+constexpr bool has_policy_type_v = has_policy_type<T>::value;
+
+template <typename T>
+constexpr bool has_backend_type_v = has_backend_type<T>::value;
+#endif
+
+template <typename D>
+char cdf(const D& ...);
+template <typename D>
+char quantile(const D& ...);
+
+template <typename D>
+struct has_cdf
+{
+   static D d;
+   static constexpr bool value = sizeof(cdf(d, 0.0f)) != 1;
+};
+
+template <typename D>
+struct has_quantile
+{
+   static D d;
+   static constexpr bool value = sizeof(quantile(d, 0.0f)) != 1;
+};
+
+template <typename D>
+struct is_distribution_imp
+{
+   static constexpr bool value =
+      has_quantile<D>::value 
+      && has_cdf<D>::value
+      && has_value_type<D>::value
+      && has_policy_type<D>::value;
+};
+
+template <typename sig, sig val>
+struct result_tag{};
+
+template <typename D>
+double test_has_location(const volatile result_tag<typename D::value_type (D::*)()const, &D::location>*);
+template <typename D>
+char test_has_location(...);
+
+template <typename D>
+double test_has_scale(const volatile result_tag<typename D::value_type (D::*)()const, &D::scale>*);
+template <typename D>
+char test_has_scale(...);
+
+template <typename D, bool b>
+struct is_scaled_distribution_helper
+{
+   static constexpr bool value = false;
+};
+
+template <typename D>
+struct is_scaled_distribution_helper<D, true>
+{
+   static constexpr bool value = 
+      (sizeof(test_has_location<D>(0)) != 1) 
+      && 
+      (sizeof(test_has_scale<D>(0)) != 1);
+};
+
+template <typename D>
+struct is_scaled_distribution_imp
+{
+   static constexpr bool value = (::boost::math::tools::detail::is_scaled_distribution_helper<D, ::boost::math::tools::detail::is_distribution_imp<D>::value>::value);
+};
+
+} // namespace detail
+
+template <typename T> struct is_distribution : public std::integral_constant<bool, ::boost::math::tools::detail::is_distribution_imp<T>::value> {};
+template <typename T> struct is_scaled_distribution : public std::integral_constant<bool, ::boost::math::tools::detail::is_scaled_distribution_imp<T>::value> {};
+
+}}}
+
+#endif
+
+