title: SwiftUI: Generic parameter 'Subject' could not be inferred
body: <p>I built a <code>LoadingView</code> with SwiftUI for showing some loading stuff in my app while I'm fetching remote data from an API. I am on Xcode Version 11.0 beta 5.</p>
  
  <p>This is the <code>LoadingView</code>:</p>
  
  <pre><code>struct LoadingView&lt;Content&gt;: View where Content: View {
  
      @Binding var isShowing: Bool
      var content: () -&gt; Content
  
      var body: some View {
  
          GeometryReader { geometry in
  
              ZStack(alignment: .center) {
  
                  self.content()
                      .disabled(self.isShowing)
                      .blur(radius: self.isShowing ? 3 : 0)
  
                  VStack {
                      Text("Loading...")
                      ActivityIndicator(isAnimating: .constant(true), style: .large)
                  }
                  .frame(width: geometry.size.width / 2,
                         height: geometry.size.height / 5)
                      .background(Color.white)
                      .foregroundColor(Color.primary)
                      .cornerRadius(5)
                      .opacity(self.isShowing ? 1 : 0)
              }
          }
      }
  }
  </code></pre>
  
  <p>This is my DataStore. It is declared as <code>ObservableObject</code> and has more than one <code>@Published</code> property. Also it does some remote fetching from an API:</p>
  
  <pre><code>class CharacterStore: ObservableObject {
  
      @Published private(set) var isLoading = false
  
  
      // Fetches some stuff from a remote api
      func fetch() {
  
          self.isLoading = true
  
          myService.getCharacters { (result) in
              DispatchQueue.main.async {
                  self.isLoading = false
              }
          }
      }
  }
  </code></pre>
  
  <p>And finally this is the View I want to show my <code>LoadingView</code> with the content of <code>ContentView</code> in it. Of course I am setting the <code>@EnvironmentObject</code> before showing this view.</p>
  
  <pre><code>struct ContentView: View {
  
      @EnvironmentObject var charStore: CharacterStore
  
      var body: some View {
  
          LoadingView(isShowing: self.$charStore.isLoading) { // Here I get the error
  
              // Show some Content here
              Text("")
          }
      }
  }
  </code></pre>
  
  <p>The problem is that I want to bind <code>self.$charStore.isLoading</code> to <code>LoadingView</code>. In this line i get the following error:</p>
  
  <blockquote>
    <p>Generic parameter 'Subject' could not be inferred</p>
  </blockquote>
  
  <p>I tried in several ways but none of these things work. Btw: If I use a <code>@State</code> property in <code>ContentView</code> it just works fine like this:</p>
  
  <pre><code>struct ContentView: View {
  
      @EnvironmentObject var charStore: CharacterStore
  
      @State var loads: Bool = false
  
      var body: some View {
  
          LoadingView(isShowing: self.$loads) { // Here I get no error
  
              // Show some Content here
              Text("")
          }
      }
  }
  </code></pre>
  
  <p>Am I missing a thing? If you need further informations let me know i can provide more content if needed.</p>
  
  <p>Thanks for the help!</p>