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On Saturday, July 11, 2015 02:23:14 AM Борис Александров wrote:
>  It seems to me that lua compares table index and
> given value by address, not by _equal metamethod

This is correct. Only the primitive 

Since the GetPlayer objects define a __tostring metamethod, you can convert the 
userdata to string for use as a table key.

The __equals metamethod wouldn't be useful for tables. Lua would need a __hash 
metamethod that returns a value suitable as a table key. But I wonder what 
strange things could happen if A==B is not the same as hash(A)==hash(B)?

And anyway you can roll your own table with meta-keys.

function objecthash(o)
    -- exercise for the reader: memoize keys for the lifetime of the object
    local mt = getmetatable(o)
    if mt and mt.__hash then
        return mt.__hash(o)
    return o
__index = function(t,o)
    return getmetatable(t).__proxy[objecthash(o)]
__newindex = function(t,o,v)
    getmetatable(t).__proxy[objecthash(o)] = v

tom <>