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digitalmars.D.learn - Getting the mutable version of a type

reply Magnus Lie Hetland <magnus hetland.org> writes:
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
Mar 02 2012
parent reply =?UTF-8?B?QWxpIMOHZWhyZWxp?= <acehreli yahoo.com> writes:
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
Mar 02 2012
parent Magnus Lie Hetland <magnus hetland.org> writes:
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
Mar 02 2012