reflect.Set() Function in Golang with Examples

// Golang program to illustrate 
// reflect.Set() Function 
   
package main 
   
import ( 
    "fmt"
    "reflect"
    "unsafe"
) 
   
// Main function 
func main() {
        var s = struct{ foo int }{654}
    var i int
 
    rs := reflect.ValueOf(&s).Elem() 
    rf := rs.Field(0)                
    ri := reflect.ValueOf(&i).Elem() 
 
    rf = reflect.NewAt(rf.Type(), unsafe.Pointer(rf.UnsafeAddr())).Elem()
    ri.Set(rf)
    rf.Set(ri)
    fmt.Println(rf) 
    fmt.Println(ri) 
     
}

// Golang program to illustrate
// reflect.Set() Function
   
package main
   
import (
    "fmt"
    "reflect"
)
  
func sum(args []reflect.Value) []reflect.Value {
    a, b := args[0], args[1]
    if a.Kind() != b.Kind() {
        fmt.Println("??? ????.")
        return nil
    }
  
    switch a.Kind() {
    case reflect.Int, reflect.Int8, reflect.Int16,
                     reflect.Int32, reflect.Int64:
        return []reflect.Value{reflect.ValueOf(a.Int() + b.Int())}

    case reflect.Uint, reflect.Uint8, reflect.Uint16, 
                      reflect.Uint32, reflect.Uint64:
        return []reflect.Value{reflect.ValueOf(a.Uint() + b.Uint())}

    case reflect.Float32, reflect.Float64:
        return []reflect.Value{reflect.ValueOf(a.Float() + b.Float())}

    case reflect.String:
        return []reflect.Value{reflect.ValueOf(a.String() + b.String())}

    default:
        return []reflect.Value{}
    }
}
  
func makeSum(fptr interface{}) {
    fn := reflect.ValueOf(fptr).Elem()
  
    v := reflect.MakeFunc(fn.Type(), sum)
  
    fn.Set(v)
}
   
// Main function
func main() {
 
    var stringSum func(string, string) string
 
    makeSum(&stringSum)
  
    fmt.Println(stringSum("Value_1 : ", "Geeks_1"))
  
}