78 lines
1.4 KiB
C++
78 lines
1.4 KiB
C++
#include <iostream>
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#include <exception>
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#include <string>
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#include <algorithm>
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class copy_tracker
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{
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int v;
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public:
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copy_tracker()
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: v(0)
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{
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std::cout << "copy_tracker::copy_tracker()" << std::endl;
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}
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copy_tracker( const copy_tracker& c )
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: v( c.v )
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{
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std::cout << "copy_tracker::copy_tracker( copy_tracker& c )" << std::endl;
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}
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void use_object()
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{
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std::cout << v << std::endl;
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}
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};
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copy_tracker copy_tracker_return_by_value2()
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{
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return copy_tracker();
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}
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copy_tracker copy_tracker_return_by_value()
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{
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return copy_tracker_return_by_value2();
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}
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void copy_tracker_pass_by_value2(copy_tracker o)
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{
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return o.use_object();
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}
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void copy_tracker_pass_by_value(copy_tracker o)
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{
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return copy_tracker_pass_by_value2(o);
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}
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void test_copy_tracker()
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{
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std::cout << "Return by value and assign." << std::endl;
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copy_tracker o = copy_tracker_return_by_value();
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std::cout << "Pass lvalue." << std::endl;
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copy_tracker_pass_by_value( o );
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std::cout << "Pass rvalue." << std::endl;
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const copy_tracker& o2 = copy_tracker_return_by_value();
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copy_tracker_pass_by_value2( o2 );
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std::cout << "Pass rvalue 2." << std::endl;
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copy_tracker_pass_by_value2( copy_tracker_return_by_value() );
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}
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int main ( void )
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{try{
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test_copy_tracker();
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return 0;
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}
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catch ( const std::exception& e )
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{
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std::cerr << std::endl
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<< "std::exception(\"" << e.what() << "\")." << std::endl;
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}
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catch ( ... )
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{
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std::cerr << std::endl
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<< "unknown exception." << std::endl;
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}}
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