Yes, this has come up before. On Fri, Nov 10, 2023 at 7:09 AM ahuigo <a132...@gmail.com> wrote:
> There is an example: https://go.dev/play/p/guzOWRKi-yp > > ``` > func (c *cachedFn[string, V]) Get0() (V, error) { > // var s any > var s string > s = "abc" // error: cannot use "abc" (untyped string constant) as string > value in assignment > fmt.Printf("cache key: %#v, %T\n", s, s) // cache key: 0, uint8 > return c.Get(s) > } > ``` > I find the generic type of the struct method a bit confusing. > 1. The type `cachedFn[string, V]` does not really constrain the type of > `s` to **string**. It's actual type is `uint8` > The type `cachedVn[string, V]` *would* in fact instantiate `cachedVn` with `string` and `V`. But that's not what you are doing. You are writing the receiver type as `fun c(c *cachedFn[string, V])`, which means that "the receiver is the generic type `cachedVn` with two type parameters called `string` and `V`". Predeclared identifiers in Go are not special in any way, you can re-use them for your own variables and types - or type parameters. So what you are doing here is fundamentally similar to this problem: https://go.dev/play/p/lDE-o7fGHi8 There probably should be a vet check for using a predeclared identifier as a type parameter name (or maybe even for any re-use of a predeclared identifier). 2. And this error is a bit strange. (`s = "abc" // error: cannot use "abc" > (untyped string constant) as string value in assignment. ` ) > > > -- > You received this message because you are subscribed to the Google Groups > "golang-nuts" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to golang-nuts+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/golang-nuts/58c92577-cb98-401a-978d-c22a1fb493ccn%40googlegroups.com > <https://groups.google.com/d/msgid/golang-nuts/58c92577-cb98-401a-978d-c22a1fb493ccn%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/CAEkBMfGJBR7QwNDyeCvp10mDhRTeGnk0T01OFq01GvgDSx8KgA%40mail.gmail.com.
