add notes on accessing named params from request.Context

Author: karlpokus

README.md

@@ -64,6 +64,8 @@ func main() {
 
 As you can see, `:name` is a *named parameter*. The values are accessible via `httprouter.Params`, which is just a slice of `httprouter.Param`s. You can get the value of a parameter either by its index in the slice, or by using the `ByName(name)` method: `:name` can be retrieved by `ByName("name")`.
 
+**Note:** Since go 1.7 you may also access named parameters from `request.Context` if you're using the `http.Handler` api. See more below under `Why doesn't this work with http.Handler?`.
+
 Named parameters only match a single path segment:
 
 ```
@@ -128,7 +130,17 @@ For even better scalability, the child nodes on each tree level are ordered by p
 
 ## Why doesn't this work with `http.Handler`?
 
-**It does!** The router itself implements the `http.Handler` interface. Moreover the router provides convenient [adapters for `http.Handler`](https://godoc.org/github.com/julienschmidt/httprouter#Router.Handler)s and [`http.HandlerFunc`](https://godoc.org/github.com/julienschmidt/httprouter#Router.HandlerFunc)s which allows them to be used as a [`httprouter.Handle`](https://godoc.org/github.com/julienschmidt/httprouter#Router.Handle) when registering a route. The only disadvantage is, that no parameter values can be retrieved when a `http.Handler` or `http.HandlerFunc` is used, since there is no efficient way to pass the values with the existing function parameters. Therefore [`httprouter.Handle`](https://godoc.org/github.com/julienschmidt/httprouter#Router.Handle) has a third function parameter.
+**It does!** The router itself implements the `http.Handler` interface. Moreover the router provides convenient [adapters for `http.Handler`](https://godoc.org/github.com/julienschmidt/httprouter#Router.Handler)s and [`http.HandlerFunc`](https://godoc.org/github.com/julienschmidt/httprouter#Router.HandlerFunc)s which allows them to be used as a [`httprouter.Handle`](https://godoc.org/github.com/julienschmidt/httprouter#Router.Handle) when registering a route.
+
+~~The only disadvantage is, that no parameter values can be retrieved when a `http.Handler` or `http.HandlerFunc` is used, since there is no efficient way to pass the values with the existing function parameters. Therefore [`httprouter.Handle`](https://godoc.org/github.com/julienschmidt/httprouter#Router.Handle) has a third function parameter.~~
+
+Since go 1.7 you can access named params from `request.Context`.
+
+```go
+params := r.Context().Value(httprouter.ParamsKey)
+// or use the helper
+params := httprouter.ParamsFromContext(r.Context())
+```
 
 Just try it out for yourself, the usage of HttpRouter is very straightforward. The package is compact and minimalistic, but also probably one of the easiest routers to set up.