61 lines
2.6 KiB
Plaintext
61 lines
2.6 KiB
Plaintext
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// Fig. 16.6: privatefragmentdemo.ixx
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// Primary module interface for a module named
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// privatefragmentdemo with a :private module fragment.
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export module privatefragmentdemo; // introduces the module name
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import <memory>; // std::unique_ptr
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class Implementation; // forward class declaration
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export class Integer { // interface class
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public:
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Integer(int value); // constructor
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int getValue() const; // gets value from hidden Implementation object
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std::unique_ptr<Implementation> getImplementationCopy();
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private:
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// pointer to object of the hidden Implementation
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std::unique_ptr<Implementation> m_ptr;
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};
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// everything from the following module :private; declaration to the end
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// of the file is hidden from importers of module privatefragmentdemo
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module :private;
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// hidden Implementation class used in the
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// Integer interface class's member function implementations
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class Implementation {
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public:
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explicit Implementation(int value) : m_value{value} {}
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int getValue() const {return m_value;}
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private:
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int m_value; // data we're hiding from the client code
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};
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// Integer interface class's member function implementations
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Integer::Integer(int value)
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: m_ptr{std::make_unique<Implementation>(value)} {}
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int Integer::getValue() const {return m_ptr->getValue();}
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// Though we return a std::unique_ptr<Implementation>, translation units
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// that import module privatefragmentdemo cannot see type Implementation.
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// Attempts to use the Implementation's members fail to compile.
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std::unique_ptr<Implementation> Integer::getImplementationCopy() {
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return std::make_unique<Implementation>(m_ptr->getValue());
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}
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/*************************************************************************
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* (C) Copyright 1992-2021 by Deitel & Associates, Inc. and *
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* Pearson Education, Inc. All Rights Reserved. *
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* *
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* DISCLAIMER: The authors and publisher of this book have used their *
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* best efforts in preparing the book. These efforts include the *
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* development, research, and testing of the theories and programs *
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* to determine their effectiveness. The authors and publisher make *
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* no warranty of any kind, expressed or implied, with regard to these *
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* programs or to the documentation contained in these books. The authors *
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* and publisher shall not be liable in any event for incidental or *
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* consequential damages in connection with, or arising out of, the *
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* furnishing, performance, or use of these programs. *
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**************************************************************************/
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