status-go/vendor/github.com/anacrolix/missinggo/v2/copy.go

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2022-03-10 09:44:48 +00:00
package missinggo
import (
"fmt"
"reflect"
)
// Copy elements from src to dst. Panics if the length of src and dst are
// different.
func CopyExact(dest interface{}, src interface{}) {
dV := reflect.ValueOf(dest)
sV := reflect.ValueOf(src)
if dV.Kind() == reflect.Ptr {
dV = dV.Elem()
}
if dV.Kind() == reflect.Array && !dV.CanAddr() {
panic(fmt.Sprintf("dest not addressable: %T", dest))
}
if sV.Kind() == reflect.Ptr {
sV = sV.Elem()
}
if sV.Kind() == reflect.String {
sV = sV.Convert(reflect.SliceOf(dV.Type().Elem()))
}
if !sV.IsValid() {
panic("invalid source, probably nil")
}
if dV.Len() != sV.Len() {
panic(fmt.Sprintf("dest len (%d) != src len (%d)", dV.Len(), sV.Len()))
}
if dV.Len() != reflect.Copy(dV, sV) {
panic("dammit")
}
}