• Aedt (10/10) Mar 26 2018 I'm a big fan of betterC. In C, you can initialize an array
• rikki cattermole (4/15) Mar 26 2018 Scroll further down.
• ag0aep6g (16/23) Mar 26 2018 The language doesn't have that feature. But there's a PR to add
• Adam D. Ruppe (10/16) Mar 26 2018 That's the equivalent of D's static arrays if a variable, and is

Aedt <adnansignsup gmail.com> writes:

I'm a big fan of betterC. In C, you can initialize an array 
without specifying the length like this
int ia[ ] = {0, 2, 1};

What is the translation of this? Note that int[] is a different 
type than C's arrays. 
https://dlang.org/spec/interfaceToC.html#data_type_compat says 
there are no equivalent to this. What's the workaround?

Also, is it possible to retrieve the pointer of the sequence of 
actual data from std.container.array? If all fails I'd like to 
use this container.

rikki cattermole <rikki cattermole.co.nz> writes:

On 26/03/2018 11:16 PM, Aedt wrote:
 I'm a big fan of betterC. In C, you can initialize an array without 
 specifying the length like this
 int ia[ ] = {0, 2, 1};
 
 What is the translation of this? Note that int[] is a different type 
 than C's arrays. 
 https://dlang.org/spec/interfaceToC.html#data_type_compat says there are 
 no equivalent to this. What's the workaround?
 
 Also, is it possible to retrieve the pointer of the sequence of actual 
 data from std.container.array? If all fails I'd like to use this container.

Scroll further down.

C: T[] -> D: T*

https://dlang.org/spec/interfaceToC.html#passing_d_array

ag0aep6g <anonymous example.com> writes:

On 03/26/2018 12:16 PM, Aedt wrote:
 I'm a big fan of betterC. In C, you can initialize an array without 
 specifying the length like this
 int ia[ ] = {0, 2, 1};
 
 What is the translation of this?

The language doesn't have that feature. But there's a PR to add 
`staticArray` to the standard library [1]. When that gets in, you can write:

     import std.array;
     auto ia = [0, 2, 1].staticArray; /* ia is an int[3] */

[...]
 Also, is it possible to retrieve the pointer of the sequence of actual 
 data from std.container.array? If all fails I'd like to use this container.

Take the address of the first element:

     import std.container.array: Array;
     Array!int a = [1, 2, 3];
     int* p = &a[0];
     assert(*p == 1);
     assert(*++p == 2);
     assert(*++p == 3);

Be aware that the pointer potentially becomes invalid when you append to 
the array.


[1] https://github.com/dlang/phobos/pull/6178

Adam D. Ruppe <destructionator gmail.com> writes:

On Monday, 26 March 2018 at 10:16:55 UTC, Aedt wrote:
 I'm a big fan of betterC. In C, you can initialize an array 
 without specifying the length like this
 int ia[ ] = {0, 2, 1};


That's the equivalent of D's static arrays if a variable, and is 
passed to C functions as a pointer. So important to note it is 
two different beasts in different contexts.

I recently wrote about this here:
https://forum.dlang.org/thread/uhibzcfwzqzqqfbrckup forum.dlang.org

so read that post for some more detail, especially with relation 
to `extern` variables.

 Also, is it possible to retrieve the pointer of the sequence of 
 actual data from std.container.array? If all fails I'd like to 
 use this container.

address of first element for that, but if you are using a 
built-in D array, you can also just `arr.ptr`.