41 lines
1.5 KiB
C++
41 lines
1.5 KiB
C++
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/// @file
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// Copyright (c) 2009-2016 Vladimir Batov.
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// Use, modification and distribution are subject to the Boost Software License,
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// Version 1.0. See http://www.boost.org/LICENSE_1_0.txt.
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#ifndef BOOST_MAKE_DEFAULT_HPP
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#define BOOST_MAKE_DEFAULT_HPP
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namespace boost
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{
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/// @details A considerable number of libraries require an instance of a class
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/// provided (storage created and initialized). For example,
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/// @code
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/// Type result;
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/// ...
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/// istream >> result;
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/// @endcode
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/// In generic code that results in the Default Constructibility requirement imposed
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/// on every type 'Type' to be used with the respective code. Inevitably, that requirement
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/// a) either excludes all the classes that for various reasons do not meet that requirement or
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/// b) imposes certain (not necessarily desirable) design/implementation onto respective classes.
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///
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/// Deployment of boost::make_default() eliminates the Default Constructibility requirement with
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/// @code
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/// Type result = boost::make_default<Type>();
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/// ...
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/// istream >> result;
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/// @endcode
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/// Classes with no default constructor can now be included via a boost::make_default() specialization:
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/// @code
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/// namespace boost
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/// {
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/// template<> inline Type make_default<Type>() { return Type(parameters); }
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/// }
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/// @endcode
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template<typename T> T make_default() { return T(); }
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}
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#endif // BOOST_MAKE_DEFAULT_HPP
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