Map literals

Map literals are like struct literals, but the keys are required.

map-literals.go

package main
import "fmt"
type Vertex struct {
    Lat, Long float64
}
var m = map[string]Vertex{
    "Bell Labs": Vertex{
        40.68433, -74.39967,
    },
    "Google": Vertex{
        37.42202, -122.08408,
    },
}
func main() {
    fmt.Println(m)
}