Function As

errutil_api.go:202–202

As finds the first error in err's chain that matches the type to which target points, and if so, sets the target to its value and returns true. An error matches a type if it is assignable to the target type, or if it has a method As(interface{}) bool such that As(target) returns true. As will panic

(err error, target interface{})

// - it also supports recursing through causes with Cause().
// - if it detects an API use error, its panic object is a valid error.
func As(err error, target interface{}) bool { return errutil.As(err, target) }

// Join returns an error that wraps the given errors.
// Any nil error values are discarded.