getting the type size of an interface

interface_size.go

package main
import (
	"fmt"
	"unsafe"
)

type (
	any interface{}
	ptr unsafe.Pointer
	goIface struct {
	    _type, _data ptr
	}
)

func ptr_size() uintptr {
    return unsafe.Sizeof(ptr(nil))
}

func print_type(n any) {
    p := ( *goIface )(ptr(&n))
    offs := uintptr(0) //ptr_size()
    itable := *( *uint )( ptr(uintptr(p._type) + offs) )
    fmt.Printf("%+v\n", itable)
}

func main() {
    print_type(int(1))  /// 8
    print_type(uint(1)) /// 8
    
    print_type(int8(0))    /// 1
    print_type(int16(0))   /// 2
    print_type(int32(0))   /// 4
    print_type(int64(0))   /// 8
    print_type(uintptr(0)) /// 8
    
    print_type(float32(0.0)) /// 4
    print_type(float64(0.0)) /// 8
	
    print_type("lololol") /// 16
    print_type([]int{})   /// 24
    print_type([9]int{})  /// 80
}