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digitalmars.D.learn - [D1] type of type

reply %u <e ee.com> writes:
Is it possible to give a function a class(type) as an argument such that the
function can call its constructor, without using templates.

void func(T t){
  new T();
}

Or, what is the type of a type? :)
Dec 23 2010
parent reply %u <e ee.com> writes:
Should have been this:

void func(type t){
  new t();
}
Dec 23 2010
next sibling parent reply "Denis Koroskin" <2korden gmail.com> writes:
On Fri, 24 Dec 2010 01:28:49 +0300, %u <e ee.com> wrote:


 Should have been this:

 void func(type t){
   new t();
 }



Try this (not tested):

class Test {}
Object o = Object.factory("Test");
Dec 23 2010
parent reply %u <e ee.com> writes:
== Quote from Denis Koroskin (2korden gmail.com)'s article

 On Fri, 24 Dec 2010 01:28:49 +0300, %u <e ee.com> wrote:

 Should have been this:

 void func(type t){
   new t();
 }



 class Test {}
 Object o = Object.factory("Test");



Thanks,
Hiding in Object.. interesting :)
Making the type a string, does this make using small class names more efficient?
Dec 23 2010
parent bearophile <bearophileHUGS lycos.com> writes:
%u:


 Hiding in Object.. interesting :)



But this has strong limitations. For this problem templates are usually used.

Bye,
bearophile
Dec 24 2010
prev sibling next sibling parent reply "Steven Schveighoffer" <schveiguy yahoo.com> writes:
On Thu, 23 Dec 2010 17:28:49 -0500, %u <e ee.com> wrote:


 Should have been this:

 void func(type t){
   new t();
 }



void func(T)(){
    new T();
}

When you are passing types into functions, use templates.

-Steve
Dec 27 2010
parent reply %u <e ee.com> writes:
== Quote from Steven Schveighoffer (schveiguy yahoo.com)'s article

 On Thu, 23 Dec 2010 17:28:49 -0500, %u <e ee.com> wrote:

 Should have been this:

 void func(type t){
   new t();
 }



     new T();
 }
 When you are passing types into functions, use templates.
 -Steve



The reason I asked for a non-templated solution is because they don't have a
common interface signature.
Dec 29 2010
next sibling parent %u <e ee.com> writes:
== Quote from Steven Schveighoffer (schveiguy yahoo.com)'s article

 On Wed, 29 Dec 2010 10:33:21 -0500, %u <e ee.com> wrote:

 == Quote from Steven Schveighoffer (schveiguy yahoo.com)'s article

 On Thu, 23 Dec 2010 17:28:49 -0500, %u <e ee.com> wrote:

 Should have been this:

 void func(type t){
   new t();
 }



     new T();
 }
 When you are passing types into functions, use templates.
 -Steve



 The reason I asked for a non-templated solution is because they don't
 have a
 common interface signature.



 interface.  This works with any type:
 void func(T)(){
     T t;
 }
 Maybe you can post an example of what you are trying to solve?
 -Steve



Yeah, sorry, I meant it the other way around: I need a common interface.

class C1: I
..
class C9: I

I'd like to pass any C(a) type to any C(b) object such that C(b) can spawn a
C(a).
What would be the common signature of these two functions?
And how would the object save the type?
Dec 29 2010
prev sibling parent %u <e ee.com> writes:
Is it not possible to have a "type" type?
Dec 29 2010
prev sibling next sibling parent "Steven Schveighoffer" <schveiguy yahoo.com> writes:
On Wed, 29 Dec 2010 10:33:21 -0500, %u <e ee.com> wrote:


 == Quote from Steven Schveighoffer (schveiguy yahoo.com)'s article

 On Thu, 23 Dec 2010 17:28:49 -0500, %u <e ee.com> wrote:

 Should have been this:

 void func(type t){
   new t();
 }



     new T();
 }
 When you are passing types into functions, use templates.
 -Steve



 The reason I asked for a non-templated solution is because they don't  
 have a
 common interface signature.



I don't know what you mean.  Templated solution does not require a common  
interface.  This works with any type:

void func(T)(){
    T t;
}

Maybe you can post an example of what you are trying to solve?

-Steve
Dec 29 2010
prev sibling parent "Steven Schveighoffer" <schveiguy yahoo.com> writes:
On Wed, 29 Dec 2010 19:25:05 -0500, %u <e ee.com> wrote:


 Is it not possible to have a "type" type?



In compile time, you can have type parameters with ease using templates.

During runtime, you can use the TypeInfo object, which is accessed via  
typeid:

auto ti = typeid(int); // ti is TypeInfo type

See docs for TypeInfo in object.di

Now, the only issue with TypeInfo is that D runtime reflection is woefully  
supported.  You can't do much with a TypeInfo.

So again, what is it you want to do with the type type?

-Steve
Dec 30 2010