Matchers can now be used as callables (#40)

Matchers can now be used as callables

hamcrest/Hamcrest/BaseMatcher.php

@@ -22,4 +22,9 @@ public function __toString()
     {
         return StringDescription::toString($this);
     }
+
+    public function __invoke()
+    {
+        return call_user_func_array(array($this, 'matches'), func_get_args());
+    }
 }

tests/Hamcrest/InvokedMatcherTest.php

@@ -0,0 +1,30 @@
+<?php
+namespace Hamcrest;
+
+
+class SampleInvokeMatcher extends BaseMatcherTest
+{
+    private $matchAgainst;
+
+    public function __construct($matchAgainst)
+    {
+        $this->matchAgainst = $matchAgainst;
+    }
+
+    public function matches($item)
+    {
+        return $item == $this->matchAgainst;
+    }
+
+}
+
+class InvokedMatcherTest extends \PHPUnit_Framework_TestCase
+{
+    public function testInvokedMatchersCallMatches()
+    {
+        $sampleMatcher = new SampleInvokeMatcher('foo');
+
+        $this->assertTrue($sampleMatcher('foo'));
+        $this->assertFalse($sampleMatcher('bar'));
+    }
+}