stabilize build system: depends, installer, boost/bdb fixes, cross targets groundwork

2026-02-24 18:38:47 +00:00
parent da8c28aaeb
commit 65cb2619a7
13106 changed files with 2484322 additions and 1804 deletions
@@ -0,0 +1,65 @@
+/*!
+@file
+Forward declares `boost::hana::ordering`.
+
+@copyright Louis Dionne 2013-2017
+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_FWD_ORDERING_HPP
+#define BOOST_HANA_FWD_ORDERING_HPP
+
+#include <boost/hana/config.hpp>
+
+
+BOOST_HANA_NAMESPACE_BEGIN
+    //! Returns a function performing `less` after applying a transformation
+    //! to both arguments.
+    //! @ingroup group-Orderable
+    //!
+    //! `ordering` creates a total order based on the result of applying a
+    //! function to some objects, which is especially useful in conjunction
+    //! with algorithms that accept a custom predicate that must represent
+    //! a total order.
+    //!
+    //! Specifically, `ordering` is such that
+    //! @code
+    //!     ordering(f) == less ^on^ f
+    //! @endcode
+    //! or, equivalently,
+    //! @code
+    //!     ordering(f)(x, y) == less(f(x), f(y))
+    //! @endcode
+    //!
+    //! @note
+    //! This is not a tag-dispatched method (hence it can't be customized),
+    //! but just a convenience function provided with the `Orderable` concept.
+    //!
+    //!
+    //! Signature
+    //! ---------
+    //! Given a Logical `Bool` and an Orderable `B`, the signature is
+    //! @f$ \mathrm{ordering} : (A \to B) \to (A \times A \to Bool) @f$.
+    //!
+    //!
+    //! Example
+    //! -------
+    //! @include example/ordering.cpp
+#ifdef BOOST_HANA_DOXYGEN_INVOKED
+    constexpr auto ordering = [](auto&& f) {
+        return [perfect-capture](auto&& x, auto&& y) -> decltype(auto) {
+            return less(f(forwarded(x)), f(forwarded(y)));
+        };
+    };
+#else
+    struct ordering_t {
+        template <typename F>
+        constexpr auto operator()(F&& f) const;
+    };
+
+    constexpr ordering_t ordering{};
+#endif
+BOOST_HANA_NAMESPACE_END
+
+#endif // !BOOST_HANA_FWD_ORDERING_HPP