From fdb300db20167a57b08456932e72d2e76d66e870 Mon Sep 17 00:00:00 2001
From: Nash Tsai <nash.tsai@gmail.com>
Date: Wed, 16 Apr 2014 01:11:50 +0800
Subject: [PATCH] add RegisteredDriverSize()

---
 driver.go | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/driver.go b/driver.go
index 209e65c4..0f1020b4 100644
--- a/driver.go
+++ b/driver.go
@@ -21,3 +21,7 @@ func RegisterDriver(driverName string, driver Driver) {
 func QueryDriver(driverName string) Driver {
 	return drivers[driverName]
 }
+
+func RegisteredDriverSize() int {
+	return len(drivers)
+}