Merge pull request #4 from firebase/getinstance

Add snippet for getting Firestore instance in cpp

Author: morganchen12

.github/workflows/firestore-ios.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: macOS-latest
     strategy:
         matrix:
-          destination: ['platform=iOS Simulator,OS=13.5,name=iPhone 11']
+          destination: ['platform=iOS Simulator,OS=latest,name=iPhone 11']
     steps:
       - name: Checkout
         uses: actions/checkout@master

firestore/ios/firestore-snippets-cpp/AppDelegate.mm

@@ -17,17 +17,25 @@
 #import "AppDelegate.h"
 #import <Firebase/Firebase.h>
 #include "firebase/app.h"
+#include "firebase/firestore.h"
+
+using firebase::App;
+using firebase::firestore::Firestore;
 
 @interface AppDelegate ()
 
 @end
 
 @implementation AppDelegate
 
-
 - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
   [FIRApp configure];
-  firebase::App::Create();
+  // [START get_firestore_instance]
+  // Make sure the call to `Create()` happens some time before you call Firestore::GetInstance().
+  App::Create();
+  Firestore* db = Firestore::GetInstance();
+  // [END get_firestore_instance]
+  (void)db; // suppress unused variable warning
   return YES;
 }