Adding MustGet method. Updating README.

README.md

@@ -294,7 +294,7 @@ func main() {
     r.Use(Logger())
 
     r.GET("/test", func(c *gin.Context){
-        example := r.Get("example").(string)
+        example := c.MustGet("example").(string)
 
         // it would print: "12345"
         log.Println(example)

gin.go

@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"github.com/julienschmidt/httprouter"
 	"html/template"
+	"log"
 	"math"
 	"net/http"
 	"path"
@@ -280,8 +281,7 @@ func (c *Context) Set(key string, item interface{}) {
 	c.Keys[key] = item
 }
 
-// Returns the value for the given key.
-// It panics if the value doesn't exist.
+// Get returns the value for the given key or an error if the key does not exist.
 func (c *Context) Get(key string) (interface{}, error) {
 	if c.Keys != nil {
 		item, ok := c.Keys[key]
@@ -292,6 +292,15 @@ func (c *Context) Get(key string) (interface{}, error) {
 	return nil, errors.New("Key does not exist.")
 }
 
+// MustGet returns the value for the given key or panics if the value doesn't exist.
+func (c *Context) MustGet(key string) interface{} {
+	value, err := c.Get(key)
+	if err != nil || value == nil {
+		log.Panicf("Key %s doesn't exist", key)
+	}
+	return value
+}
+
 /************************************/
 /******** ENCOGING MANAGEMENT********/
 /************************************/