move 'is' method to the str class where it belongs.

laravel/str.php

@@ -300,6 +300,30 @@ class Str {
 		return substr(str_shuffle(str_repeat(static::pool($type), 5)), 0, $length);
 	}
 
+	/**
+	 * Determine if a given string matches a given pattern.
+	 *
+	 * @param  string  $pattern
+	 * @param  string  $value
+	 * @return bool
+	 */
+	public static function is($pattern, $value)
+	{
+		// Asterisks are translated into zero-or-more regular expression wildcards
+		// to make it convenient to check if the URI starts with a given pattern
+		// such as "library/*". This is only done when not root.
+		if ($pattern !== '/')
+		{
+			$pattern = str_replace('*', '(.*)', $pattern).'\z';
+		}
+		else
+		{
+			$pattern = '^/$';
+		}
+
+		return preg_match('#'.$pattern.'#', $value);
+	}
+
 	/**
 	 * Get the character pool for a given type of random string.
 	 *