• Peter Thomassen (11/11) Aug 14 2006 Hi,
• Sean Kelly (5/17) Aug 14 2006 bool* test = null;
• Peter Thomassen (6/10) Aug 15 2006 This looks nice ... but how do I read / write the value of test? After
• Sean Kelly (8/16) Aug 15 2006 The other suggestion to use an enum is a better one. To use the bool
• Peter Thomassen (3/7) Aug 15 2006 And how would I set it false?
• Chris Nicholson-Sauls (3/14) Aug 15 2006 *test = false;
• Peter Thomassen (3/6) Aug 16 2006 I'm that stupid -- thanks.
• Chris Miller (13/24) Aug 14 2006 =
• Unknown W. Brackets (19/34) Aug 14 2006 Just remember, D is not PHP :).

Peter Thomassen <info peter-thomassen.de> writes:

Hi,

the following doesn't work:

bit test; 
test = null; 
 
I understand that this is not possible, but coming from the PHP world, I'm
looking for a way to define that "test" hasn't got a value yet, not even
true or false.

Is that possible? Is there a workaround?

Thanks!
Peter

Sean Kelly <sean f4.ca> writes:

Peter Thomassen wrote:
 Hi,
 
 the following doesn't work:
 
 bit test; 
 test = null; 
  
 I understand that this is not possible, but coming from the PHP world, I'm
 looking for a way to define that "test" hasn't got a value yet, not even
 true or false.
 
 Is that possible? Is there a workaround?

     bool* test = null;

     test = new bool;

(note that bit has been replaced by bool in recent versions of D)


Sean

Peter Thomassen <info peter-thomassen.de> writes:

Sean Kelly schrieb am Dienstag, 15. August 2006 03:34:
      bool* test = null;
 
      test = new bool;

This looks nice ... but how do I read / write the value of test? After
assigning "new bool", reading it gives a memory address, and writing fails.
Maybe I should've posted to digitalmars.D.learn :-)

 (note that bit has been replaced by bool in recent versions of D)

Thanks.
Peter

Sean Kelly <sean f4.ca> writes:

Peter Thomassen wrote:
 Sean Kelly schrieb am Dienstag, 15. August 2006 03:34:
      bool* test = null;

      test = new bool;

 
 This looks nice ... but how do I read / write the value of test? After
 assigning "new bool", reading it gives a memory address, and writing fails.
 Maybe I should've posted to digitalmars.D.learn :-)

The other suggestion to use an enum is a better one.  To use the bool 
above you have to dereference the pointer:

     if( test !is null && *test )
     {
         // something that requires test to be set and true
     }


Sean

Peter Thomassen <info peter-thomassen.de> writes:

Sean Kelly schrieb am Dienstag, 15. August 2006 23:59:
      if( test !is null && *test )
      {
          // something that requires test to be set and true
      }

And how would I set it false?

Peter

Chris Nicholson-Sauls <ibisbasenji gmail.com> writes:

Peter Thomassen wrote:
 Sean Kelly schrieb am Dienstag, 15. August 2006 23:59:
 
     if( test !is null && *test )
     {
         // something that requires test to be set and true
     }

 
 
 And how would I set it false?
 
 Peter

*test = false;

-- Chris Nicholson-Sauls

Peter Thomassen <info peter-thomassen.de> writes:

Chris Nicholson-Sauls schrieb am Mittwoch, 16. August 2006 02:01:
 And how would I set it false?

 
 *test = false;

I'm that stupid -- thanks.

Peter

"Chris Miller" <chris dprogramming.com> writes:

On Mon, 14 Aug 2006 21:22:54 -0400, Peter Thomassen  =

<info peter-thomassen.de> wrote:

 Hi,

 the following doesn't work:

 bit test;
 test =3D null;
 I understand that this is not possible, but coming from the PHP world,=

  =

 I'm
 looking for a way to define that "test" hasn't got a value yet, not ev=

en
 true or false.

 Is that possible? Is there a workaround?

 Thanks!
 Peter


Perhaps bool/bit isn't even what you want.

enum Foo: byte
{
    None,
    True,
    False,
}

Foo f =3D Foo.None;

and this requires no heap allocation or extra storage.

"Unknown W. Brackets" <unknown simplemachines.org> writes:

Just remember, D is not PHP :).

As it would happen, the way PHP/Zend does it is using a struct:

enum zval_type
{
	IS_NULL,
	IS_STRING,
	IS_INTEGER,
}

struct zval
{
	zval_type type = zval_type.IS_NULL;
	union
	{
		char[] str_val = null;
		int int_val = 0;
	}
}

I'm also primarily a PHP programmer, by the way ;).

-[Unknown]


 Hi,
 
 the following doesn't work:
 
 bit test; 
 test = null; 
  
 I understand that this is not possible, but coming from the PHP world, I'm
 looking for a way to define that "test" hasn't got a value yet, not even
 true or false.
 
 Is that possible? Is there a workaround?
 
 Thanks!
 Peter