I'm writing a template for generating data of some possibly immutable type -- e.g., a string. What I'm wondering is, is there some way of accessing the mutable version of an immutable type?

I mean, I could do something like (for strings and related immutable arrays)...

void func(T)(ref immutable(T)[] arg) {
   T[] res;
   ...
   arg = cast(immutable(T)[]) res;
}

But it would be useful to be able to write the same template for both mutable and immutable types, and just use something like

void func(T)(ref T arg) {
   mutable(T) res;
   ...
   arg = cast(T) res;
}

Is there something like that? (E.g., a template in Phobos or something.) I guess I could do a match with an is() expression to extract the type, perhaps.


-- 
Magnus Lie Hetland
http://hetland.org

On 03/02/2012 02:18 AM, Magnus Lie Hetland wrote:
> I'm writing a template for generating data of some possibly immutable
> type -- e.g., a string. What I'm wondering is, is there some way of
> accessing the mutable version of an immutable type?

Yes, std.traits.Unqual:

  http://dlang.org/phobos/std_traits.html#Unqual

import std.stdio;
import std.traits;

void foo(T)()
{
    Unqual!T temp;
    writeln(typeof(temp).stringof);
}

void main()
{
    foo!(immutable int)();
}

Ali

On 2012-03-02 11:23:20 +0000, Ali Çehreli said:

> On 03/02/2012 02:18 AM, Magnus Lie Hetland wrote:
>> I'm writing a template for generating data of some possibly immutable
>> type -- e.g., a string. What I'm wondering is, is there some way of
>> accessing the mutable version of an immutable type?
> 
> Yes, std.traits.Unqual:
> 
>    http://dlang.org/phobos/std_traits.html#Unqual

Aah -- awesome. Thanks!

-- 
Magnus Lie Hetland
http://hetland.org