In Go prior to generics, interface{} is an escape hatch less frequently needed but not necessarily much safer than void*. Post generics, interface{} is suddenly more useful and will be aliased by ‘any’.
The way the std lib heap works in Go, an implementation doesn’t have to mention interface{}. Using the Go std lib solution is about satisfying a few interfaces, defining some methods for sorting and swapping over the element type. The use of interface{} is internal.
Go’s generics solution is going to have type constraints, which I think will be very familiar to some and probably new to others … So, the Go generics PQ should still require some constraints on elements, not ’any’thing will work. I’ve really enjoyed constraints in languages and it’s not quite natural in C++/Java, but Go’s interfaces already do some ‘constraint’ work conceptually and can be used as constraints in Go’s generics syntax. I’m interested to see how this plays out.