• DLearner (29/29) Jan 08 2023 I thought dynamic arrays were unavailable under -betterC.
• Richard (Rikki) Andrew Cattermole (6/6) Jan 08 2023 Dynamic arrays are not.
• areYouSureAboutThat (4/6) Jan 08 2023 See the 'Retained Features' section, and the 'Unavailable
• ryuukk_ (3/32) Jan 08 2023 That example is working for me
• DLearner (21/40) Jan 11 2023 ```
• Richard (Rikki) Andrew Cattermole (7/7) Jan 11 2023 Makes sense, you wrote a main function which only applies to having a

DLearner <bmqazwsx123 gmail.com> writes:

I thought dynamic arrays were unavailable under -betterC.

Example_02:
```
extern(C) void main() {
    import core.stdc.stdio : printf;
    int[] A;
    printf("Hello betterC\n");
}
```

```
dmd -betterC -run Example_02
```

Expected result: Failure at compilation stage, owing to presence 
of dynamic array A, when -betterC set.
Actual result: Ran to completion, dislaying the message.

Example_03:
```
void main() {
    import core.stdc.stdio : printf;
    int[] A;
    printf("Hello betterC\n");
}
```

```
dmd -betterC -run Example_03
```

Expected result: Failure at compilation stage, owing to presence 
of dynamic array A, when -betterC set.
Actual result: Failed at link (not compilation) stage.

"Richard (Rikki) Andrew Cattermole" <richard cattermole.co.nz> writes:

Dynamic arrays are not.

Slices are.

A slice is a pointer + length pair; it requires no runtime 
infrastructure to manipulate.

A dynamic array, has slices that reference internal state in the GC 
which is where all the manipulation takes place (like appending).

areYouSureAboutThat <areYouSureAboutThat gmail.com> writes:

On Sunday, 8 January 2023 at 13:49:22 UTC, DLearner wrote:
 I thought dynamic arrays were unavailable under -betterC.
 .. ...

See the 'Retained Features' section, and the 'Unavailable 
Features' section

https://dlang.org/spec/betterc.html

ryuukk_ <ryuukk.dev gmail.com> writes:

On Sunday, 8 January 2023 at 13:49:22 UTC, DLearner wrote:
 I thought dynamic arrays were unavailable under -betterC.

 Example_02:
 ```
 extern(C) void main() {
    import core.stdc.stdio : printf;
    int[] A;
    printf("Hello betterC\n");
 }
 ```

 ```
 dmd -betterC -run Example_02
 ```

 Expected result: Failure at compilation stage, owing to 
 presence of dynamic array A, when -betterC set.
 Actual result: Ran to completion, dislaying the message.

 Example_03:
 ```
 void main() {
    import core.stdc.stdio : printf;
    int[] A;
    printf("Hello betterC\n");
 }
 ```

 ```
 dmd -betterC -run Example_03
 ```

 Expected result: Failure at compilation stage, owing to 
 presence of dynamic array A, when -betterC set.
 Actual result: Failed at link (not compilation) stage.

That example is working for me

What's the exact code you wrote?

DLearner <bmqazwsx123 gmail.com> writes:

On Sunday, 8 January 2023 at 23:59:21 UTC, ryuukk_ wrote:
[...]
 Example_03:
 ```
 void main() {
    import core.stdc.stdio : printf;
    int[] A;
    printf("Hello betterC\n");
 }
 ```

 ```
 dmd -betterC -run Example_03
 ```

 Expected result: Failure at compilation stage, owing to 
 presence of dynamic array A, when -betterC set.
 Actual result: Failed at link (not compilation) stage.

 That example is working for me

 What's the exact code you wrote?

```
void main() {
    import core.stdc.stdio : printf;
    int[] A;
    printf("Hello betterC\n");
}
```

Result:

```
C:\Users\SoftDev\Documents\BDM\D\BetterC>dmd -betterC -run 
Example_03
lld-link: error: undefined symbol: __d_run_main
 referenced by Example_03.obj:(_main)



Error: linker exited with status 1
```

Compiler version:
```
C:\Users\SoftDev\Documents\BDM\D\BetterC>dmd --version
DMD32 D Compiler v2.100.2-dirty
```

"Richard (Rikki) Andrew Cattermole" <richard cattermole.co.nz> writes:

Makes sense, you wrote a main function which only applies to having a 
druntime.

For -betterC, use the libc's main function:

```d
extern(C) void main() {

}
```