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

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

@@ -0,0 +1,69 @@
+/*!
+@file
+Forward declares `boost::hana::remove_if`.
+
+@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_REMOVE_IF_HPP
+#define BOOST_HANA_FWD_REMOVE_IF_HPP
+
+#include <boost/hana/config.hpp>
+#include <boost/hana/core/when.hpp>
+
+
+BOOST_HANA_NAMESPACE_BEGIN
+    //! Remove all the elements of a monadic structure that satisfy some
+    //! predicate.
+    //! @ingroup group-MonadPlus
+    //!
+    //! Given a monadic structure `xs` and a unary predicate, `remove_if`
+    //! returns a new monadic structure equal to `xs` without all its elements
+    //! that satisfy the predicate. This is equivalent to `filter` with a
+    //! negated predicate, i.e.
+    //! @code
+    //!     remove_if(xs, predicate) == filter(xs, negated predicated)
+    //! @endcode
+    //!
+    //!
+    //! Signature
+    //! ---------
+    //! Given a MonadPlus `M` and a predicate of type \f$ T \to Bool \f$ for
+    //! some compile-time Logical `Bool`, the signature is
+    //! \f$
+    //!     \mathrm{remove\_if} : M(T) \times (T \to Bool) \to M(T)
+    //! \f$
+    //!
+    //! @param xs
+    //! A monadic structure to remove some elements from.
+    //!
+    //! @param predicate
+    //! A unary predicate called as `predicate(x)`, where `x` is an element
+    //! of the structure, and returning whether `x` should be removed from
+    //! the structure. In the current version of the library, `predicate`
+    //! must return a compile-time Logical.
+    //!
+    //!
+    //! Example
+    //! -------
+    //! @include example/remove_if.cpp
+#ifdef BOOST_HANA_DOXYGEN_INVOKED
+    constexpr auto remove_if = [](auto&& xs, auto&& predicate) {
+        return tag-dispatched;
+    };
+#else
+    template <typename M, typename = void>
+    struct remove_if_impl : remove_if_impl<M, when<true>> { };
+
+    struct remove_if_t {
+        template <typename Xs, typename Pred>
+        constexpr auto operator()(Xs&& xs, Pred&& pred) const;
+    };
+
+    constexpr remove_if_t remove_if{};
+#endif
+BOOST_HANA_NAMESPACE_END
+
+#endif // !BOOST_HANA_FWD_REMOVE_IF_HPP