golang_empty_struct

golang_empty_struct

// the empty struct consumes zero bytes
// see: https://dave.cheney.net/2014/03/25/the-empty-struct
// see: https://github.com/bradfitz/iter

package main

import (
	"fmt"
	"strconv"
	"unsafe"
)

func main() {
	var emtpyStruct struct{}
	fmt.Println("size of empty struct:", unsafe.Sizeof(emtpyStruct)) // prints 0

	var x [1000000000]struct{}
	fmt.Println("size of huge slice of empty structs:", unsafe.Sizeof(x)) // prints 0

	s := N(5)
	s[0] = struct{}{}
	fmt.Println("len=" + strconv.Itoa(len(s)) + " cap=" + strconv.Itoa(cap(s)))
	for i := range s {
		fmt.Println(i)
	}
}

func N(n int) []struct{} {
	return make([]struct{}, n)
}