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When
we explicitly define either a copy constructor or an
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assignment
operator in a derived class, we are responsible
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for
ensuring that the base class copy constructor and
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assignment
operator are called. This is because when we
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implement
our own copy constructor or assignment
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operator,
the compiler no longer provides an implicit one
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and
cannot guarantee that the base class copy constructor
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or
assignment op are called.
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| • |
For
the copy constructor, we specify the base class' copy
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constructor
in the initialization list of the derived class'
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copy
constructor.
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student::student(const student
&s) : checking(s) {
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...
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• This works because a student object is a checking object; checking’s
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constructor my be implicit or explicitly defined.
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