title: Dictionary in constructor for a mutable struct in Julia
body: <p>Is it possible to initialize a mutable struct with a variable which is a dict.I am trying the following:</p>
  
  <pre><code>mutable struct Global
      speciesCnt::Int64
      chromosomeCnt::Int64
      nodeCnt::Int64
      innov_number::Int64
      innovations::Dict{(Int64,Int64),Int64}
      cf::Config
      function Global(cf::Config)
          new(0,0,0,0,Dict{(Int64,Int64),Int64}(),cf) # global dictionary
      end
  end
  </code></pre>
  
  <p>however, when I run it I get the following error:</p>
  
  <p>LoadError: TypeError: in Type, in parameter, expected Type, got Tuple{DataType,DataType}.</p>
  
  <p>Any help is greatly appreciated.
  I am using Julia v 1.0</p>