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 +1,85 @@
+/*!
+@file
+Defines `boost::hana::drop_front_exactly`.
+
+@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_DROP_FRONT_EXACTLY_HPP
+#define BOOST_HANA_DROP_FRONT_EXACTLY_HPP
+
+#include <boost/hana/fwd/drop_front_exactly.hpp>
+
+#include <boost/hana/bool.hpp>
+#include <boost/hana/concept/integral_constant.hpp>
+#include <boost/hana/concept/iterable.hpp>
+#include <boost/hana/config.hpp>
+#include <boost/hana/core/dispatch.hpp>
+#include <boost/hana/drop_front.hpp>
+#include <boost/hana/integral_constant.hpp>
+#include <boost/hana/is_empty.hpp>
+
+
+BOOST_HANA_NAMESPACE_BEGIN
+    //! @cond
+    template <typename Xs, typename N>
+    constexpr auto drop_front_exactly_t::operator()(Xs&& xs, N const& n) const {
+        using It = typename hana::tag_of<Xs>::type;
+        using DropFrontExactly = BOOST_HANA_DISPATCH_IF(drop_front_exactly_impl<It>,
+            hana::Iterable<It>::value &&
+            hana::IntegralConstant<N>::value
+        );
+
+    #ifndef BOOST_HANA_CONFIG_DISABLE_CONCEPT_CHECKS
+        static_assert(hana::Iterable<It>::value,
+        "hana::drop_front_exactly(xs, n) requires 'xs' to be an Iterable");
+
+        static_assert(hana::IntegralConstant<N>::value,
+        "hana::drop_front_exactly(xs, n) requires 'n' to be an IntegralConstant");
+    #endif
+
+        static_assert(N::value >= 0,
+        "hana::drop_front_exactly(xs, n) requires 'n' to be non-negative");
+
+        return DropFrontExactly::apply(static_cast<Xs&&>(xs), n);
+    }
+
+    template <typename Xs>
+    constexpr auto drop_front_exactly_t::operator()(Xs&& xs) const {
+        return (*this)(static_cast<Xs&&>(xs), hana::size_c<1>);
+    }
+    //! @endcond
+
+    namespace detail {
+        template <typename Xs, typename N>
+        constexpr void check_dfe_overflow(Xs const& xs, N const&, hana::true_) {
+            constexpr bool n_overflew_length = decltype(
+                hana::is_empty(hana::drop_front(xs, hana::size_c<N::value - 1>))
+            )::value;
+            static_assert(!n_overflew_length,
+            "hana::drop_front_exactly(xs, n) requires 'n' to be less than or "
+            "equal to the number of elements in 'xs'");
+        }
+
+        template <typename Xs, typename N>
+        constexpr void check_dfe_overflow(Xs const&, N const&, hana::false_) { }
+    }
+
+    template <typename It, bool condition>
+    struct drop_front_exactly_impl<It, when<condition>> : default_ {
+        template <typename Xs, typename N>
+        static constexpr auto apply(Xs&& xs, N const& n) {
+            auto result = hana::drop_front(static_cast<Xs&&>(xs), n);
+            constexpr bool check_for_overflow =
+                decltype(hana::is_empty(result))::value && N::value != 0;
+
+            detail::check_dfe_overflow(xs, n, hana::bool_c<check_for_overflow>);
+
+            return result; // NRVO applied
+        }
+    };
+BOOST_HANA_NAMESPACE_END
+
+#endif // !BOOST_HANA_DROP_FRONT_EXACTLY_HPP