Default extra.go template

extra.go

// go has a lot of copy-paste code. most of the time you can't _just_ alias your code globally. extra.go file 
// is standard template of frequently used aliases.  

package somepkg


type null = struct{}

// any is just alias to interface{} for better looking code (like `x := []any{1,'2',"three"}` looks better 
// than `x := []interface{}{...}`) 
//
// NOTE: after go 1.18, use constraints, DON'T use this alias, it looks as weird, as any other part of this 
// file
type any = interface{}

// incomparable is a zero-width, non-comparable type. Adding it to a struct
// makes that struct also non-comparable, and generally doesn't add
// any size (as long as it's first).
type incomparable [0]func()


func check(err error) {
	if err != nil {
		panic(err)
	}
}


// Embed this type into a struct, which mustn't be copied,
// so `go vet` gives a warning if this struct is copied.
//
// See https://github.com/golang/go/issues/8005#issuecomment-190753527 for details.
// and also: https://stackoverflow.com/questions/52494458/nocopy-minimal-example
type noCopy struct{}

func (*noCopy) Lock()   {}
func (*noCopy) Unlock() {}