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// Copyright (C) 2005-2006 Alain Miniussi <alain.miniussi -at->.

// Use, modification and distribution is subject to the Boost Software
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at

// Message Passing Interface 1.1 -- Section 4. MPI Collectives

/** @file inplace.hpp
 *  This header provides helpers to indicate to MPI collective operation
 *  that a buffer can be use both as an input and output.

#include <boost/mpi/communicator.hpp>
#include <vector>

namespace boost { namespace mpi {

 *  @brief Wrapper type to explicitly indicate that a input data 
 * can be overriden with an output value.
template <typename T>
struct inplace_t {
  inplace_t(T& inout) : buffer(inout) {}
  T& buffer;

template <typename T>
struct inplace_t<T*> {
  inplace_t(T* inout) : buffer(inout) {}
  T* buffer;

 *  @brief Wrapp a input data to indicate that it can be overriden 
 *  with an ouput value.
 *  @param inout the contributing input value, it will be overriden 
 *  with the output value where one is expected. If it is a pointer, 
 *  the number of elements will be provided separatly.
 *  @returns The wrapped value or pointer.
template<typename T>
inplace(T& inout) { 
  return inplace_t<T>(inout);
 * \overload
template<typename T>
inplace(T* inout) { 
  return inplace_t<T*>(inout);
} }  // end namespace boost::mpi