Most languages would encode such behavior in a trait or a protocol instead of a zero-length struct field. It's type information and ought to be encoded in the type. From that perspective, I think it is a hack.

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kbolino 4 hours ago | parent | next [-]

This feels like a style complaint and not one about substance. An inaccessible (because it's named _) zero-length struct field is just another kind of metadata. It also doesn't require you to pollute the method set, which would be a bigger issue.

The real hack to me is that anything which simply has Lock() and Unlock() methods is considered uncopyable.

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reorder9695 4 hours ago | parent [-]

Coming from Rust anyway (can't say I'm familiar with Go), nothing about having it as a trait would pollute the method set, traits don't have to have methods (e.g. pin, unpin, send, sync, etc.). Yes a zero length field can be metadata and this is a style complaint but a struct's fields are traditionally its data and the type is its metadata, I feel like it's harmful to mix these two as I at least wouldn't generally look at fields to find metadata for the struct.

	▲	rcxdude 25 minutes ago \| parent \| next [-]
		Rust has similar zero-sized-types, probably the most 'magical' being PhantomData.
	▲	kbolino 3 hours ago \| parent \| prev \| next [-]
		Interfaces in Go (the closest equivalent to traits in Rust) don't have to have methods either, but they are structurally typed. This is like "static duck typing" if you will. So an interface with no methods is implemented by every type in the language (indeed, this became such a useful pattern that the name "any" was reserved for it in Go 1.18). Marker interfaces can exist in Go, but here they are another kind of hack. They must define at least one method (which doesn't have to be public), though that method is never actually meant to be called.
	▲	woadwarrior01 3 hours ago \| parent \| prev [-]
		I'm only peripherally familiar with Go. IIRC, Rust defaults to move-only structs with the option to make them copyable with the Copy trait. Swift defaults to copyable structs (like Go), but has a ~Copyable generic type constraint to make them move-only.

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stevecoalbear 3 hours ago | parent | prev [-]

Go's entire schtick is being simple, eschewing language complexity in favour of letting the programmer handle it themself. Like C, but with pointer safety and garbage collection.

We learned from C++ and Rust that languages can be so smart that people can't effectively use them. Go is the opposite. It's so dumb that anyone can use it, but it doesn't have some native language features you might want.

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insanitybit 3 hours ago | parent [-]

How is this simple? It's basically a hint to `go vet` that uses a special interface pattern. I'm baffled by what some people call "simple" lol

	▲	a2ff6eeb0 an hour ago \| parent [-]
		How much additional complexity do users need to be aware of when writing new code because of the way this was implemented? Adding new features makes the language bigger, for something that Claude tells me is used 20 times in total in the entire Go codebase.