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58 lines
1.7 KiB
C++
58 lines
1.7 KiB
C++
// -- reference_wrappers - Boost Tuple Library -----------------------------
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// Copyright (C) 1999, 2000 Jaakko Järvi (jaakko.jarvi@cs.utu.fi)
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//
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// Permission to copy, use, sell and distribute this software is granted
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// provided this copyright notice appears in all copies.
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// Permission to modify the code and to distribute modified code is granted
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// provided this copyright notice appears in all copies, and a notice
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// that the code was modified is included with the copyright notice.
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//
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// This software is provided "as is" without express or implied warranty,
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// and with no claim as to its suitability for any purpose.
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//
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// For more information, see http://www.boost.org
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// -----------------------------------------------------------------
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#ifndef BOOST_TUPLE_REFERENCE_WRAPPERS_HPP
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#define BOOST_TUPLE_REFERENCE_WRAPPERS_HPP
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namespace boost {
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// reference wrappers -------------------------------------------------------
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// These wrappers are handle classes that hold references to objects.
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// reference_wrapper is used to specify that a tuple element should be
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// a reference to the wrapped object - rather than a copy of it.
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// The wrapper acts as a disguise for passing non-const reference
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// parameters via a reference to const parameter.
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template<class T>
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class reference_wrapper {
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T& x;
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public:
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explicit
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reference_wrapper(T& t) : x(t) {}
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operator T&() const { return x; }
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};
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// store as a reference to T
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template<class T>
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inline const reference_wrapper<T> ref(T& t) {
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return reference_wrapper<T>(t);
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}
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// store as a reference to const T
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template<class T>
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inline const reference_wrapper<const T> cref(const T& t) {
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return reference_wrapper<const T>(t);
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}
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} // end of namespace boost
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#endif // BOOST_TUPLE_REFERENCE_WRAPPERS_HPP
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