Re: Life time of an object and Reference Var
"@velu".invalid wrote:
class Foo
{
};
Foo& getFoo ( void )
{
Foo* objptr = new Foo;
return objptr;
} ;
int main ( void )
{
Foo &ref = getFoo( );
}
will this code work ?
It won't even compile. You are trying to return a Foo* from a function
that returns a Foo&.
If you correct this to
Foo& getFoo ()
{
Foo* objptr = new Foo;
return *objptr;
}
the code will work, but it is very bad practice. Who is responsible for
deleting the dynamically allocated Foo object? Returning a reference
does not signal a transfer of ownership. It is also not exception-safe.
The standard, exception-safe way of doing it would be something like:
#include <memory>
class Foo {};
typedef std::auto_ptr<Foo> FooPtr;
FooPtr getFoo ()
{
return FooPtr (new Foo);
}
int main ()
{
FooPtr foo (getFoo () );
// main now owns foo and uses it
// ...
// foo will be automatically deleted here, even when
// an exception is thrown before
}
--
Gerhard Menzl
#dogma int main ()
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