• RedCAT (11/11) Jul 15 2017 I have only TypeInfo taken dynamically from an arbitrary type,
• =?UTF-8?Q?Ali_=c3=87ehreli?= (21/26) Jul 16 2017 I'm afraid there is no way of setting the value of Variant dynamically

RedCAT <andronkin gmail.com> writes:

I have only TypeInfo taken dynamically from an arbitrary type, 
and I need to initialize the Variant variable to the default 
value for this type. How can I do that?

I tried this:

TypeInfo ti = typeid(int);
Variant v = ti.initializer;

But after,

int o = v.get!int;

and

int o = v.coerce!int;

doesn't work.

=?UTF-8?Q?Ali_=c3=87ehreli?= <acehreli yahoo.com> writes:

On 07/15/2017 09:27 AM, RedCAT wrote:
 I have only TypeInfo taken dynamically from an arbitrary type, and I
 need to initialize the Variant variable to the default value for this
 type.

I'm afraid there is no way of setting the value of Variant dynamically 
because it wants to do type-checking at compile time. You should be able 
to use a switch-case statement yourself because presumably you have the 
set of valid types:

     // (Not compiled.)
     switch (ti) {
     case typeid(int):
         o = v.get!int;

 TypeInfo ti = typeid(int);
 Variant v = ti.initializer;

TypeInfo.initializer returns an array of bytes (no type clue there):

     /**
      * Return default initializer.  If the type should be initialized 
to all
      * zeros, an array with a null ptr and a length equal to the type 
size will
      * be returned. For static arrays, this returns the default 
initializer for
      * a single element of the array, use `tsize` to get the correct size.
      */
     abstract const(void)[] initializer() nothrow pure const  safe  nogc;

Ali