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Improving Performance Of Virtual Functions
Submitted by
One of the things that can end up costing performance is
the overhead of calling the base class in a virtual function.
One trick I've used for that is inline virtual functions,
which may sound contradictory but it's not. Consider:
class Foo
{
virtual bool IsA( TypeID Type ) { return Type == TypeFoo; };
};
class Bar : public Foo
{
virtual bool IsA( TypeID Type );
};
void Bar::IsA( TypeID Type )
{
return (Type == TypeBar) || Foo::IsA( Type );
}
Since the compiler knows exactly which function to call
when you say Foo::IsA it can inline the definition of
the function.
-------------------------------------------------------
Don Neufeld - Programmer - Verant Interactive St. Louis
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