how does Go infer types

content

type MySlice []string
func Clone[E any](s []E) []E {
	return append([]E(nil), s...)
}
ms := MySlice{"hello", "world"}
ms2 := Clone(ms)

in go-unnamed-type, it’s explained that ms is type MySlice, but ms2 is []string
for Clone
- Clone is a generic function, Go needs to infer the type of input argument
- Clone is expecting a list of any type: arg is []E, and E is any
when we passed in MySlice to Clone:
- Go sees it’s NOT []E
- so it tries to see through the E passed in, which is MySlice in this case
- by see through, Go finds the underlying type of MySlice, which is []string
- Go decides that E in this call is string
that’s why the function returns []string (which is []E with E being string)