Added new 'resolvable' and 'isAlias' methods to the container.

src/Illuminate/Container/Container.php

@@ -58,6 +58,17 @@ class Container implements ArrayAccess {
 	 */
 	protected $globalResolvingCallbacks = array();
 
+	/**
+	 * Determine if a given string is resolvable.
+	 *
+	 * @param  string  $abstract
+	 * @return bool
+	 */
+	protected function resolvable($abstract)
+	{
+		return $this->bound($abstract) || $this->isAlias($abstract);
+	}
+
 	/**
 	 * Determine if the given abstract type has been bound.
 	 *
@@ -69,6 +80,17 @@ public function bound($abstract)
 		return isset($this[$abstract]) || isset($this->instances[$abstract]);
 	}
 
+	/**
+	 * Determine if a given string is an alias.
+	 *
+	 * @param  string  $name
+	 * @return bool
+	 */
+	public function isAlias($name)
+	{
+		return isset($this->aliases[$name]);
+	}
+
 	/**
 	 * Register a binding with the container.
 	 *

src/Illuminate/Foundation/changes.json

@@ -35,7 +35,8 @@
 		{"message": "Cloned Eloquent query builders now clone the underlying query builder.", "backport": null},
 		{"message": "Allow for passing of custom attributes into Validator::make as fourth parameter.", "backport": null},
 		{"message": "Allow comma delimited list of queues to be passed to queue:listen / queue:work to implement queue priority.", "backport": null},
-		{"message": "When new bindings are added to container, old aliases bound to that key will now be dropped.", "backport": null}
+		{"message": "When new bindings are added to container, old aliases bound to that key will now be dropped.", "backport": null},
+		{"message": "Added new 'resolvable' and 'isAlias' methods to the container.", "backport": null}
 	],
 	"4.0.x": [
 		{"message": "Added implode method to query builder and Collection class.", "backport": null},