Hi Mohamed,
The memory layout of "string" is the same as that of "struct { string }",
so there is no extra allocation or indirection involved on creation and
access, hence no runtime overhead.
Peter
On Fri, Nov 8, 2019 at 2:01 AM Mohamed Yousif <mmbu...@gmail.com> wrote:
> Hi Speter,
>
> Can you elaborate more on this point please?
> > there is no memory or runtime overhead due to encapsulating the string
> within a struct.
>
>
> On Thu, 7 Nov 2019 at 3:15 PM, speter <speter....@gmail.com> wrote:
>
>> Hi bsr,
>>
>> I'd suggest to use a struct type with a single string field. It will
>> prevent conversion from untyped string constant "by mistake".
>> Moreover, if you make the string field unexported, you can limit new
>> instance creation to the declaring package, allowing to enforce predefined
>> values.
>> Unlike with some other languages, there is no memory or runtime overhead
>> due to encapsulating the string within a struct.
>>
>> HTH,
>> Peter
>>
>> On Thu, Nov 7, 2019 at 7:58 PM bsr <bsr...@gmail.com> wrote:
>>
>>> Hello,
>>>
>>> I am a long time user of go, but I always had the impression that below
>>> code would not work as string and Status are different type.
>>> I thought I need to explicitly convert as ```exec(Status("abc"))``` it
>>> to work.
>>>
>>> I think, this part of the spec may be the reason
>>> https://golang.org/ref/spec#Assignability
>>>
>>> - x is an untyped constant <https://golang.org/ref/spec#Constants>
>>> representable <https://golang.org/ref/spec#Representability> by a
>>> value of type T.
>>>
>>> Is there a way I can prevent this behavior.
>>> I am using Status like an enum, and only predefined status values should
>>> be allowed.
>>>
>>>
>>>
>>>
>>> https://play.golang.org/p/4zsb7KtPBC6
>>>
>>> package main
>>>
>>> import (
>>> "fmt"
>>> )
>>>
>>> type Status string
>>>
>>> func main() {
>>> exec("abc")
>>> }
>>>
>>> func exec(s Status) {
>>> fmt.Printf("Hello, %s", s)
>>> }
>>>
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