-

icr(0.23.1) > init = {"Joe" => {"age" => 34}}
 => {"Joe" => {"age" => 34}}
icr(0.23.1) > [["Bob", {"age" => 55}]].reduce(init) { |memo, (k,v)| memo[k] = v ; memo}
no overload matches 'Hash(String, Hash(String, Int32))#[]=' with types (Hash(String, Int32) | String), (Hash(String, Int32) | String)
Overloads are:
 - Hash(K, V)#[]=(key : K, value : V)
Couldn't find overloads for these types:
 - Hash(String, Hash(String, Int32))#[]=(key : Hash(String, Int32), value : Hash(String, Int32))
 - Hash(String, Hash(String, Int32))#[]=(key : Hash(String, Int32), value : String)
 - Hash(String, Hash(String, Int32))#[]=(key : String, value : String)