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 * 
 * Licensed to the Apache Software Foundation (ASF) under one
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 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
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 *************************************************************/

#ifndef SYSTEM_STL_FUNCTIONAL
#define SYSTEM_STL_FUNCTIONAL

#if defined(HAVE_STL_INCLUDE_PATH)
	// TODO: use computed include file name
	#include_next <functional>
#elif defined(_MSC_VER)
	#include <../../VC/include/functional>
	namespace std { using tr1::hash; }
#if 0 // TODO: enable only when std::_Swap_adl is not available
	// note: VS2008SP1 has known problems after a security update (KB971092,KB974479,KB974223)
	namespace std{ template<class _T> void _Swap_adl(_T& l, _T& r) {swap(l,r);} }
#endif	
#else // fall back to boost/tr1
	#include <boost/tr1/tr1/functional>
	#include <boost/functional/hash.hpp>
#endif


#ifndef NO_STLPORT4_EMULATION

namespace std
{
// emulate SGI extensions to the STL using http://www.sgi.com/tech/stl/stl_function.h as reference
template< typename T> struct identity : unary_function<T,T> { T operator()(const T& t) const { return t;} };
template< typename T, typename U> struct project2nd : public binary_function<T,U,U> { U operator()(const T&, const U& u) const { return u;}};
template<typename P> struct select1st : public unary_function<P, typename P::first_type> { const typename P::first_type& operator()(const P& p) const { return p.first; }};
template<typename P> struct select2nd : public unary_function<P, typename P::second_type> { const typename P::second_type& operator()(const P& p) const { return p.second; }};

#if (defined(_MSC_VER) && (_MSC_VER >= 1600)) || defined(__GXX_EXPERIMENTAL_CXX0X__)
template<typename T> inline T&& forward( typename identity<T>::type&& t) { return t; }
#endif // C++11 move semantics

template<typename Op1, typename Op2> class unary_compose : public unary_function<typename Op2::argument_type, typename Op1::result_type> 
{
protected:
	Op1 aOp1;
	Op2 aOp2;
public:
	unary_compose( const Op1& rOp1, const Op2& rOp2) : aOp1(rOp1), aOp2(rOp2) {}
	typename Op1::result_type operator()( const typename Op2::argument_type& x) const { return aOp1(aOp2(x)); }
};

template<typename Op1, typename Op2> inline unary_compose<Op1,Op2> compose1( const Op1& rOp1, const Op2& rOp2) { return unary_compose<Op1,Op2>(rOp1, rOp2); }

} // namespace std

#endif // NO_STLPORT4_EMULATION

#endif