Is there non-broken serialization of complex types in nim?

[readysloth]

Hi all.

I resently asked a [question](https://forum.nim-lang.org/t/6153) about how can 
i serialize type like `table[A, Hash_set[A]]` in nim. I used standard marhal 
package (and still want to stick to standard library), but i can't deserialize 
it after serialization.

When i try to, runtime crashes with 
    
    
    /usr/lib/nim/pure/marshal.nim (333) to
    /usr/lib/nim/pure/marshal.nim (266) loadAny
    /usr/lib/nim/pure/marshal.nim (179) loadAny
    /usr/lib/nim/pure/parsejson.nim (522) raiseParseErr
    Error: unhandled exception: unknown file(1,1) Error: '{' expected for an 
object expected [JsonParsingError]
    
    
    Run

But '{' is in place!

This is how i try to deserialize it: 
    
    
    let deserialized = read_file("serialized.json").to[:Table[A, Hash_set[A]]
    
    
    Run

BTW it doesn't work even for simple types like strings or ints :(