July 15
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.


5 days ago
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