   template.registerInBaseContext("succ", Box(succ))
 
   // Renders "2", "3", "4"
-  var rendering: String
-  rendering = template.render(Box(["x": 1]))!
-  rendering = template.render(Box(["x": 2.0]))!
-  rendering = template.render(Box(["x": NSNumber(float: 3.1415)]))!
+  template.render(Box(["x": 1]))!
+  template.render(Box(["x": 2.0]))!
+  template.render(Box(["x": NSNumber(float: 3.1415)]))!
 
   // Error evaluating {{ succ(x) }} at line 1: Unexpected argument type
   var error: NSError?

  template.registerInBaseContext("strong", Box(strong))

  // Renders "<strong>Hello Arthur</strong>"
  let rendering = template.render(Box(["name": Box("Arthur")]))!

RenderFunction is invoked for both {{ variable }} and {{# section }}...{{/}}
tags. You can query info.tag.type in order to have a different rendering

      // Renders "0 is falsey. 1 is truthy."
      let template = Template(string: "{{#numbers}}{{.}} is {{#.}}truthy{{^}}falsey{{/}}.{{/}}")!
      let data = ["numbers": [0, 1]]
      template.render(Box(data))!
    
    GRMustache makes sure Int and NSNumber wrapping integers have the same
    behavior: whatever the actual type of boxed numbers, your templates render
