https://run.dlang.io/is/s4cfiv

onlineapp.d(23): Error: static variable A cannot be read at compile time
onlineapp.d(23): Error: cannot implicitly convert expression 1 of type int to int*

I see no reason the code should not work,  and the second error message make no sense.

please suggestion how should I made this code to work.

On Wed, Jun 12, 2019 at 01:12:58PM +0000, Newbie2019 via Digitalmars-d-learn wrote:
> https://run.dlang.io/is/s4cfiv
> 
> onlineapp.d(23): Error: static variable A cannot be read at compile time
> onlineapp.d(23): Error: cannot implicitly convert expression 1 of type int
> to int*
> 
> I see no reason the code should not work,  and the second error message make no sense.

Read: https://wiki.dlang.org/User:Quickfur/Compile-time_vs._compile-time


T

-- 
A mathematician is a device for turning coffee into theorems. -- P. Erdos

On Wednesday, 12 June 2019 at 13:53:09 UTC, H. S. Teoh wrote:
> On Wed, Jun 12, 2019 at 01:12:58PM +0000, Newbie2019 via Digitalmars-d-learn wrote:
> Read: https://wiki.dlang.org/User:Quickfur/Compile-time_vs._compile-time
>
>
> T


Thanks for the tips.

I move the static array into local var then it work.

Still the last error message make no sense here.

On Wednesday, 12 June 2019 at 14:09:08 UTC, Newbie2019 wrote:
> On Wednesday, 12 June 2019 at 13:53:09 UTC, H. S. Teoh wrote:
>> On Wed, Jun 12, 2019 at 01:12:58PM +0000, Newbie2019 via Digitalmars-d-learn wrote:
>> Read: https://wiki.dlang.org/User:Quickfur/Compile-time_vs._compile-time
>>
>>
>> T
>
>
> Thanks for the tips.
>
> I move the static array into local var then it work.

You keep a static variable then initilizae it at module's static this() { },

something like this:


struct Arguments {
        int     verbose;
}
__gshared Arguments A;

__gshared option[1] long_options;

static this()
{
     long_options =  [option(cast(char*)("verbose".ptr), no_argument,  &A.verbose, 1)];
}


> Still the last error message make no sense here.

It's the call to struct constructor that you're missing. Those C-style array initialziation doesn't work with D (as far I know) so that you have to explicit (and I like it, even if C-style did work in D, I wouldn't use) so you have to call the constructor as I did in below code. Anothing type error is: "verbose" is of D's string type, not a raw pointer as in C and you need in your struct member. To get that, use D's .ptr property then cast away immutable to get the const char* you need.

I guess you're implementing a command-line parsing? if you aren't aware of, D has something in its standard library for that: https://dlang.org/phobos/std_getopt.html might be helpful.

That being said, if you find tedious to build an array with default values for specific struct members, you can automate all that with D CTFE or just use derived struct with default members. Things here do not need to be like C at high-level :)