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

depends/x86_64-pc-linux-gnu/include/boost/hana/fwd/count.hpp

@@ -0,0 +1,57 @@
+/*!
+@file
+Forward declares `boost::hana::count`.
+
+@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_COUNT_HPP
+#define BOOST_HANA_FWD_COUNT_HPP
+
+#include <boost/hana/config.hpp>
+#include <boost/hana/core/when.hpp>
+
+
+BOOST_HANA_NAMESPACE_BEGIN
+    //! Return the number of elements in the structure that compare equal to
+    //! a given value.
+    //! @ingroup group-Foldable
+    //!
+    //! Given a Foldable structure `xs` and a value `value`, `count` returns
+    //! an unsigned integral, or a Constant thereof, representing the number
+    //! of elements of `xs` that compare equal to `value`. For this method to
+    //! be well-defined, all the elements of the structure must be Comparable
+    //! with the given value.
+    //!
+    //!
+    //! @param xs
+    //! The structure whose elements are counted.
+    //!
+    //! @param value
+    //! A value compared with each element in the structure. Elements
+    //! that compare equal to this value are counted, others are not.
+    //!
+    //!
+    //! Example
+    //! -------
+    //! @include example/count.cpp
+#ifdef BOOST_HANA_DOXYGEN_INVOKED
+    constexpr auto count = [](auto&& xs, auto&& value) {
+        return tag-dispatched;
+    };
+#else
+    template <typename T, typename = void>
+    struct count_impl : count_impl<T, when<true>> { };
+
+    struct count_t {
+        template <typename Xs, typename Value>
+        constexpr auto operator()(Xs&& xs, Value&& value) const;
+    };
+
+    constexpr count_t count{};
+#endif
+BOOST_HANA_NAMESPACE_END
+
+#endif // !BOOST_HANA_FWD_COUNT_HPP