[simiones]

Given that there is no way to make a non-pointer map in Go, there is no workaround for the example they gave.

The broader point is that there is no way in Go to ensure that data passed over a channel will not be modified concurrently without modifying the type of the data specifically for the channel use case.

A deep_copy() primitive would fix this.

[bankisan]

Right, but they mentioned sending immutable structs which is why I gave the struct example. But you're right that every declared map is a just a pointer.

With respect to your second point, I see what you mean but I still don't think that's a negative of Go. You can pass in copied values without having to have a deep_copy() primitive (loop map values and copy to new map, dereferencing a pointer, etc.). Like other parts of Go, if you want to make your data immutable there is no syntactic sugar. You have to explicitly write it out.

[simiones]

> With respect to your second point, I see what you mean but I still don't think that's a negative of Go.

It is a negative of Go, because Go pushes you into the pit of failure by its design: it is much, much harder to do the right thing (send deep copies of objects over channels) than it is to do the wrong things (send pointers or shallow copies over channels).

[eru]

You'd have to roll your own deep_copy by hand (or code generation) for every single data type.

[eru]

Yes, either a deep_copy() or a way to declare things immutable. (Or both.)