Copying one symbol into another

Question

I would like to know how can I completely copy one Symbol to another. When I say copy, a refer to UpValues, DownValues, FormatValues.. and so on.

I created this function to do that, but I don't know if it's a good practice.

SetAttributes[copy,HoldFirst];
copy[new_Symbol,org_Symbol]:=Module[{},
    ClearAll@new;
    UpValues@new=UpValues@org/.org:> new;
    DownValues@new=DownValues@org/.org:> new;
    FormatValues@new=FormatValues@org/.org:> new;
    SetAttributes[new,Attributes[org]];
]

So I can copy some symbol b into a using a~copy~b.

There is a simpler way to do that? Or this approach is ok?

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Update

Thanks for all comments. This is the evolution of the function above:

SetAttributes[copy,HoldFirst];
new_~copy~org_:=With[{prop={Attributes,UpValues, OwnValues, DownValues, SubValues, NValues, FormatValues, Messages,Options}},
    ClearAll@new;
    Set[#@new,#@org/.HoldPattern@org:>new]&~Scan~prop;
]

Answer 1

This is a simplification of your solution:

Language`ExtendedFullDefinition[new] = 
 Language`ExtendedFullDefinition[old] /. HoldPattern[old] :> new

I believe Language`ExtendedFullDefinition is used in transferring definitions between the main kernel and subkernels. Also note the HoldPattern on the LHS of the rule which ensures that OwnValues will work.

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One thing to think about is: what should happen if old refers back to itself? Should new keep referring to old, or to itself? This solution, like yours, replaces the old in the definition as well.