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The
dynamic_cast operator relies on information stored in
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an
object by the compiler whenever a direct or indirect
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base
class contains a virtual function. This cast is used
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when
downcasting to determine at run time if the
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downcast
is valid or not.
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The
dynamic_cast operator syntax is
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dynamic_cast<type*>(expr)
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where expr is an expression pointing
to a direct or
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indirect
base class object and type is a derived class.
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expr
is converted to a pointer of the specified type if the
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dynamic
type of the object pointed to is that type or is a
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type
derived from that type. Otherwise, the result of the
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cast
operation is zero.
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