There is a prerequisite to transfer ownership: it must be proved that
no other values share ownership of the byte slice returned by
ioutil.ReadFile.
On Saturday, September 12, 2020 at 3:42:14 AM UTC-4 tapi...@gmail.com wrote:
> Is it good to introduce owner transfer based string<->[]byte conversions?
> After the conversion, the being converted string/[]byte values mustn't be
> used any more.
> Such as
>
> tlsCertData, _ = ioutil.ReadFile("/etc/ssl/mycert")
> var tlsCert string = bultin.ByteSlice2String(tlsCertData)
>
> // forbid using tlsCertData any more
> _ = tlsCertData // error: tlsCertData can only used after a re-assignment.
>
> On Friday, September 11, 2020 at 3:09:57 PM UTC-4 Ian Lance Taylor wrote:
>
>> On Fri, Sep 11, 2020 at 9:45 AM Kevin Chadwick <m8il...@gmail.com> wrote:
>> >
>> > I apologise if this has already been discussed. Google didn't turn up
>> anything
>> > directly related.
>> >
>> > If you read a file using the following that returns a byte slice.
>> >
>> > tlsCertb, err := ioutil.ReadFile("/etc/ssl/mycert")
>> > if err != nil {
>> > log.Fatal(err)
>> > }
>> > tlsCert = string(tlsCertb)
>> >
>> > Is there a way to get a string without the cast.
>> >
>> > Otherwise couldn't the language automatically return a string rather
>> than a byte
>> > slice in these cases if the receiving var is already a string?
>> >
>> > e.g.
>> >
>> > var string tlsCert
>> > tlsCert, err = ioutil.ReadFile("/etc/ssl/mycert")
>> > if err != nil {
>> > log.Fatal(err)
>> > }
>>
>> The way Go works, ioutil.ReadFile is compiled with the io/ioutil
>> package. It can't change based on how it is called. So it is always
>> going to return []byte.
>>
>> The only way to implement what you suggest would be to add an implicit
>> conversion from []byte to string. But that seems problematic. In
>> general Go avoids implicit conversions except to interface types. And
>> a conversion to string does require a copy, so it doesn't seem like a
>> great idea to do that implicitly.
>>
>> If this happens a lot in your code, it seems easy enough to use a tiny
>> helper function.
>>
>> Ian
>>
>
--
You received this message because you are subscribed to the Google Groups
"golang-nuts" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to golang-nuts+unsubscr...@googlegroups.com.
To view this discussion on the web visit
https://groups.google.com/d/msgid/golang-nuts/af63dbc8-188a-46f6-aa7c-e2c44d17cf37n%40googlegroups.com.
