1 files changed, 75 insertions, 0 deletions
diff --git a/boost/hana/not.hpp b/boost/hana/not.hpp
new file mode 100644
index 0000000000..87ff508b29
--- /dev/null
+++ b/boost/hana/not.hpp
@@ -0,0 +1,75 @@
+/*!
+@file
+Defines `boost::hana::not_`.
+
+@copyright Louis Dionne 2013-2016
+Distributed under the Boost Software License, Version 1.0.
+(See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
+ */
+
+#ifndef BOOST_HANA_NOT_HPP
+#define BOOST_HANA_NOT_HPP
+
+#include <boost/hana/fwd/not.hpp>
+
+#include <boost/hana/concept/constant.hpp>
+#include <boost/hana/concept/logical.hpp>
+#include <boost/hana/config.hpp>
+#include <boost/hana/core/to.hpp>
+#include <boost/hana/core/dispatch.hpp>
+#include <boost/hana/detail/canonical_constant.hpp>
+
+#include <type_traits>
+
+
+BOOST_HANA_NAMESPACE_BEGIN
+    //! @cond
+    template <typename X>
+    constexpr decltype(auto) not_t::operator()(X&& x) const {
+        using Bool = typename hana::tag_of<X>::type;
+        using Not = BOOST_HANA_DISPATCH_IF(hana::not_impl<Bool>,
+            hana::Logical<Bool>::value
+        );
+
+    #ifndef BOOST_HANA_CONFIG_DISABLE_CONCEPT_CHECKS
+        static_assert(hana::Logical<Bool>::value,
+        "hana::not_(cond) requires 'cond' to be a Logical");
+    #endif
+
+        return Not::apply(static_cast<X&&>(x));
+    }
+    //! @endcond
+
+    template <typename L, bool condition>
+    struct not_impl<L, when<condition>> : hana::default_ {
+        template <typename ...Args>
+        static constexpr auto apply(Args&& ...) = delete;
+    };
+
+    template <typename L>
+    struct not_impl<L, hana::when<std::is_arithmetic<L>::value>> {
+        template <typename Cond>
+        static constexpr Cond apply(Cond const& cond)
+        { return static_cast<Cond>(cond ? false : true); }
+    };
+
+    namespace detail {
+        template <typename C, typename X>
+        struct constant_from_not {
+            static constexpr auto value = hana::not_(hana::value<X>());
+            using hana_tag = detail::CanonicalConstant<typename C::value_type>;
+        };
+    }
+
+    template <typename C>
+    struct not_impl<C, hana::when<
+        hana::Constant<C>::value &&
+        hana::Logical<typename C::value_type>::value
+    >> {
+        template <typename Cond>
+        static constexpr auto apply(Cond const&)
+        { return hana::to<C>(detail::constant_from_not<C, Cond>{}); }
+    };
+BOOST_HANA_NAMESPACE_END
+
+#endif // !BOOST_HANA_NOT_HPP