ceph/src/boost/boost/hana/fwd/fill.hpp

   1 /*!
   2 @file
   3 Forward declares `boost::hana::fill`.
   4
   5 @copyright Louis Dionne 2013-2017
   6 Distributed under the Boost Software License, Version 1.0.
   7 (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
   8  */
   9
  10 #ifndef BOOST_HANA_FWD_FILL_HPP
  11 #define BOOST_HANA_FWD_FILL_HPP
  12
  13 #include <boost/hana/config.hpp>
  14 #include <boost/hana/core/when.hpp>
  15
  16
  17 BOOST_HANA_NAMESPACE_BEGIN
  18     //! Replace all the elements of a structure with a fixed value.
  19     //! @ingroup group-Functor
  20     //!
  21     //!
  22     //! Signature
  23     //! ---------
  24     //! Given `F` a Functor, the signature is
  25     //! \f$
  26     //!     \mathtt{fill} : F(T) \times U \to F(U)
  27     //! \f$
  28     //!
  29     //! @param xs
  30     //! The structure to fill with a `value`.
  31     //!
  32     //! @param value
  33     //! A value by which every element `x` of the structure is replaced,
  34     //! unconditionally.
  35     //!
  36     //!
  37     //! Example
  38     //! -------
  39     //! @include example/fill.cpp
  40 #ifdef BOOST_HANA_DOXYGEN_INVOKED
  41     constexpr auto fill = [](auto&& xs, auto&& value) {
  42         return tag-dispatched;
  43     };
  44 #else
  45     template <typename Xs, typename = void>
  46     struct fill_impl : fill_impl<Xs, when<true>> { };
  47
  48     struct fill_t {
  49         template <typename Xs, typename Value>
  50         constexpr auto operator()(Xs&& xs, Value&& value) const;
  51     };
  52
  53     constexpr fill_t fill{};
  54 #endif
  55 BOOST_HANA_NAMESPACE_END
  56
  57 #endif // !BOOST_HANA_FWD_FILL_HPP