Declaring complex variable defaults

Can somebody show me how to declare default variable values for a complex variable, as I 've not been able to work out the syntax as I keep getting error. Ideally, I also only want to declare default for objects is_fifo and content_based_deduplication, but if it has to be all objects so be it. TIA.

variable “queues” {
type = map(object({
name = string
purpose = string
is_fifo = bool
content_based_deduplication = bool
permissions = set(string)
sqs_policy = string
}))
default = {

}
}