Hi,

could you have a look whether this is a bug with tupleof?
In case you have a const string with a default value,
the attribute is not in the tupleof list.

struct A {
	const string a = "abc";
	string d;
}

void main(){
	assert(A().tupleof.length == 2); // fails -> length = 1
}

Kind regards
André

On Thursday, 13 February 2014 at 16:37:20 UTC, Andre wrote:
> Hi,
>
> could you have a look whether this is a bug with tupleof?
> In case you have a const string with a default value,
> the attribute is not in the tupleof list.
>
> struct A {
> 	const string a = "abc";
> 	string d;
> }
>
> void main(){
> 	assert(A().tupleof.length == 2); // fails -> length = 1
> }
>
> Kind regards
> André

I'm not sure. May guess is the compiler figures that you'll never be able to change a and pulls it out of the struct. What I don't know is, if it should do this without using immutable or enum.

Besides: I don't think that const elements make any sense. What do you want to do?

Am 13.02.2014 17:42, schrieb Tobias Pankrath:
> On Thursday, 13 February 2014 at 16:37:20 UTC, Andre wrote:
>> Hi,
>>
>> could you have a look whether this is a bug with tupleof?
>> In case you have a const string with a default value,
>> the attribute is not in the tupleof list.
>>
>> struct A {
>>     const string a = "abc";
>>     string d;
>> }
>>
>> void main(){
>>     assert(A().tupleof.length == 2); // fails -> length = 1
>> }
>>
>> Kind regards
>> André
>
> I'm not sure. May guess is the compiler figures that you'll never be
> able to change a and pulls it out of the struct. What I don't know is,
> if it should do this without using immutable or enum.
>
> Besides: I don't think that const elements make any sense. What do you
> want to do?

It is strange, const string attributes without a value are working fine.

The use case is for communication with a database procedure. The database procedure want the request in JSON format. I created the
structure similiar to the JSON request and serialize it to JSON.
Some of the values should be constant others should be variable.

Kind regards
André

Andre:

> could you have a look whether this is a bug with tupleof?
> In case you have a const string with a default value,
> the attribute is not in the tupleof list.
>
> struct A {
> 	const string a = "abc";
> 	string d;
> }
>
> void main(){
> 	assert(A().tupleof.length == 2); // fails -> length = 1
> }

Tupleeof is working correctly here. Currently const/immutable fields don't become struct instance fields. After a transition phase this will be changed, and in some months you will see two fields there. DMD 2.065 has a warning on this.

Bye,
bearophile

On Thursday, 13 February 2014 at 16:52:58 UTC, bearophile wrote:
> Andre:
>
>> could you have a look whether this is a bug with tupleof?
>> In case you have a const string with a default value,
>> the attribute is not in the tupleof list.
>>
>> struct A {
>> 	const string a = "abc";
>> 	string d;
>> }
>>
>> void main(){
>> 	assert(A().tupleof.length == 2); // fails -> length = 1
>> }
>
> Tupleeof is working correctly here. Currently const/immutable fields don't become struct instance fields. After a transition phase this will be changed, and in some months you will see two fields there. DMD 2.065 has a warning on this.
>
> Bye,
> bearophile

Don't you mean const/immutable fields with initialisers don't become instance fields? Or is this actually as strange as it sounds?

Am 13.02.2014 17:52, schrieb bearophile:
> Andre:
>
>> could you have a look whether this is a bug with tupleof?
>> In case you have a const string with a default value,
>> the attribute is not in the tupleof list.
>>
>> struct A {
>>     const string a = "abc";
>>     string d;
>> }
>>
>> void main(){
>>     assert(A().tupleof.length == 2); // fails -> length = 1
>> }
>
> Tupleeof is working correctly here. Currently const/immutable fields
> don't become struct instance fields. After a transition phase this will
> be changed, and in some months you will see two fields there. DMD 2.065
> has a warning on this.
>
> Bye,
> bearophile


Thanks for the info. Time to update to 2.065:)

Kind regards
André

On Thursday, 13 February 2014 at 16:57:19 UTC, John Colvin wrote:
> Don't you mean const/immutable fields with initialisers don't become instance fields? Or is this actually as strange as it sounds?

Yes, it is legacy behavior (== bug) that persisted since D1 days and was addressed only recently. Until this deprecation/transition process will end this:

struct X
{
    const string value = "literal"'
}

is effectively same as this:

struct X
{
    enum value = "literal"'
}

On Thursday, 13 February 2014 at 17:12:28 UTC, Dicebot wrote:
> On Thursday, 13 February 2014 at 16:57:19 UTC, John Colvin wrote:
>> Don't you mean const/immutable fields with initialisers don't become instance fields? Or is this actually as strange as it sounds?
>
> Yes, it is legacy behavior (== bug) that persisted since D1 days and was addressed only recently. Until this deprecation/transition process will end this:
>
> struct X
> {
>     const string value = "literal";
> }
>
> is effectively same as this:
>
> struct X
> {
>     enum value = "literal";
> }

To be anal, it's technically the same as:

struct X
{
     static const string value = "literal";
}

The immutable/const member will be made a static member, which
you can deference, or pass by reference.