s_cherry_e/sr/tool/test/cast/cast_test.go

package main

import (
	"fmt"
	"runtime"
	"testing"
	"unsafe"
)

type T1 struct {
	f1 int8  // 1 byte
	f2 int64 // 8 bytes
	f3 int32 // 4 bytes
}

type T2 struct {
	f1 int8  // 1 byte
	f3 int32 // 4 bytes
	f2 int64 // 8 bytes
}

func TestSizeOf(t *testing.T) {
	fmt.Println(runtime.GOARCH) // amd64

	t1 := T1{}
	fmt.Println(unsafe.Sizeof(t1)) // 24 bytes

	t2 := T2{}
	fmt.Println(unsafe.Sizeof(t2)) // 16 bytes
}

type People interface {
	Show1()
}

type Student struct {
}

func (*Student) Show1() {
}

func live() People {
	var su *Student
	return su
}

func TestPeople(t *testing.T) {
	b := live()
	fmt.Printf("%v \n", b)

	if b == nil {
		fmt.Println("a")
	} else {
		fmt.Println("b")
	}
}