How to enable Google Maps zoom controls using Swift

I think @Scriptable is right, the documentation hasn't a section for Zoom Controls for iOS SDK.

Well, I made my own (and very basic) controls.

Keep this order (MapView, Button, Button), else, you can't see the buttons.

First one, you must select your UIVIew and change the class to GSMMapView

and, in the MapViewController

import Foundation
import UIKit
import GoogleMaps

class MapViewController: UIViewController {

    struct Place {
        let id: Int
        let name: String
        let lat: CLLocationDegrees
        let lng: CLLocationDegrees
        let icon: String
    }

    @IBOutlet weak var mapView: GMSMapView!
    var markerDict: [Int: GMSMarker] = [:]

    var zoom: Float = 15

    override func viewDidLoad() {
        super.viewDidLoad()

        let camera = GMSCameraPosition.camera(withLatitude: 34.1381168, longitude: -118.3555723, zoom: zoom)
        self.mapView.camera = camera

        do {
            if let styleURL = Bundle.main.url(forResource: "style", withExtension: "json") {
                mapView.mapStyle = try GMSMapStyle(contentsOfFileURL: styleURL)
            } else {
                NSLog("Unable to find style.json")
            }
        } catch {
            NSLog("One or more of the map styles failed to load. \(error)")
        }

        let places = [
            Place(id: 0, name: "MrMins", lat: 34.1331168, lng: -118.3550723, icon: "i01"),
        ]

        for place in places {
            let marker = GMSMarker()
            marker.position = CLLocationCoordinate2D(latitude: place.lat, longitude: place.lng)
            marker.title = place.name
            marker.snippet = "Custom snipet message \(place.name)"
            marker.appearAnimation = kGMSMarkerAnimationPop
            //marker.icon = self.imageWithImage(image: UIImage(named: place.icon)!, scaledToSize: CGSize(width: 35.0, height: 35.0))
            marker.map = self.mapView

            markerDict[place.id] = marker
        }

    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }



    @IBAction func btnZoomIn(_ sender: Any) {
        zoom = zoom + 1
        self.mapView.animate(toZoom: zoom)
    }

    @IBAction func btnZoomOut(_ sender: Any) {
        zoom = zoom - 1
        self.mapView.animate(toZoom: zoom)
    }


}