Yes, it currently requires two lookups (two hashes, two bucket searches,
etc.). This general problem is issue 17133
(https://github.com/golang/go/issues/17133). Your example has the extra
complication that the update operation is an append, not just a +=.
On Sunday, November 27, 2016 at 7:00
Yes you will get two map operations happen, one lookup and one assign.
Wrapping the code into a (mildly modified for pretty output) runnable
example: https://play.golang.org/p/oGKvfS9ssH
In the basic case of a new key, there is no way to avoid doing both a
lookup and assign, but in the case where
