ceph/src/boost/libs/mpi/include/boost/mpi/inplace.hpp

   1 // Copyright (C) 2005-2006 Alain Miniussi <alain.miniussi -at- oca.eu>.
   2
   3 // Use, modification and distribution is subject to the Boost Software
   4 // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
   5 // http://www.boost.org/LICENSE_1_0.txt)
   6
   7 // Message Passing Interface 1.1 -- Section 4. MPI Collectives
   8
   9 /** @file inplace.hpp
  10  *
  11  *  This header provides helpers to indicate to MPI collective operation
  12  *  that a buffer can be use both as an input and output.
  13  */
  14 #ifndef BOOST_MPI_INPLACE_HPP
  15 #define BOOST_MPI_INPLACE_HPP
  16
  17 #include <boost/mpi/communicator.hpp>
  18 #include <vector>
  19
  20 namespace boost { namespace mpi {
  21
  22 /**
  23  *  @brief Wrapper type to explicitly indicate that a input data
  24  * can be overriden with an output value.
  25  */
  26 template <typename T>
  27 struct inplace_t {
  28   inplace_t(T& inout) : buffer(inout) {}
  29   T& buffer;
  30 };
  31
  32 template <typename T>
  33 struct inplace_t<T*> {
  34   inplace_t(T* inout) : buffer(inout) {}
  35   T* buffer;
  36 };
  37
  38
  39 /**
  40  *  @brief Wrapp a input data to indicate that it can be overriden
  41  *  with an ouput value.
  42  *  @param inout the contributing input value, it will be overriden
  43  *  with the output value where one is expected. If it is a pointer,
  44  *  the number of elements will be provided separatly.
  45  *  @returns The wrapped value or pointer.
  46  */
  47 template<typename T>
  48 inplace_t<T>
  49 inplace(T& inout) {
  50   return inplace_t<T>(inout);
  51 }
  52 /**
  53  * \overload
  54  */
  55 template<typename T>
  56 inplace_t<T*>
  57 inplace(T* inout) {
  58   return inplace_t<T*>(inout);
  59 }
  60 } }  // end namespace boost::mpi
  61
  62 #endif // BOOST_MPI_INPLACE_HPP
  63