99 lines
2.0 KiB
C++
99 lines
2.0 KiB
C++
//////////////////////////////////////////////////////////////////////////////
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//
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// (C) Copyright Ion Gaztanaga 2014-2014.
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// Distributed under the Boost Software License, Version 1.0.
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// (See accompanying file LICENSE_1_0.txt or copy at
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// http://www.boost.org/LICENSE_1_0.txt)
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//
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// See http://www.boost.org/libs/move for documentation.
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//
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//////////////////////////////////////////////////////////////////////////////
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#include <boost/move/detail/config_begin.hpp>
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#include <boost/move/detail/meta_utils_core.hpp>
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#include <boost/move/move.hpp>
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//[template_assign_example_foo_bar
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class Foo
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{
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BOOST_COPYABLE_AND_MOVABLE(Foo)
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public:
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int i;
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explicit Foo(int val) : i(val) {}
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Foo(BOOST_RV_REF(Foo) obj) : i(obj.i) {}
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Foo& operator=(BOOST_RV_REF(Foo) rhs)
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{ i = rhs.i; rhs.i = 0; return *this; }
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Foo& operator=(BOOST_COPY_ASSIGN_REF(Foo) rhs)
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{ i = rhs.i; return *this; } //(1)
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template<class U> //(*) TEMPLATED ASSIGNMENT, potential problem
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//<-
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#if 1
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typename ::boost::move_detail::disable_if_same<U, Foo, Foo&>::type
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operator=(const U& rhs)
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#else
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//->
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Foo& operator=(const U& rhs)
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//<-
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#endif
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//->
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{ i = -rhs.i; return *this; } //(2)
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};
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//]
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struct Bar
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{
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int i;
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explicit Bar(int val) : i(val) {}
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};
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//<-
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#ifdef NDEBUG
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#undef NDEBUG
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#endif
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//->
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#include <cassert>
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int main()
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{
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//[template_assign_example_main
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Foo foo1(1);
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//<-
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assert(foo1.i == 1);
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//->
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Foo foo2(2);
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//<-
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assert(foo2.i == 2);
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Bar bar(3);
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assert(bar.i == 3);
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//->
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foo2 = foo1; // Calls (1) in C++11 but (2) in C++98
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//<-
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assert(foo2.i == 1);
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assert(foo1.i == 1); //Fails in C++98 unless workaround is applied
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foo1 = bar;
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assert(foo1.i == -3);
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foo2 = boost::move(foo1);
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assert(foo1.i == 0);
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assert(foo2.i == -3);
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//->
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const Foo foo5(5);
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foo2 = foo5; // Calls (1) in C++11 but (2) in C++98
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//<-
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assert(foo2.i == 5); //Fails in C++98 unless workaround is applied
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assert(foo5.i == 5);
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//->
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//]
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return 0;
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}
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#include <boost/move/detail/config_end.hpp>
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