• Ki Rill (26/26) Sep 18 2023 I've been trying out std containers. Checked Phobos code - all
• Richard (Rikki) Andrew Cattermole (3/3) Sep 18 2023 Yeah that is to be expected, things working in -betterC from
• Jonathan M Davis (9/46) Sep 18 2023 -betterC is really only intended to make it easier to port C code to D, ...

Ki Rill <rill.ki yahoo.com> writes:

I've been trying out std containers. Checked Phobos code - all 
seems to be  nogc. Good. Then I try out this and it fails because 
something throws in array construction and that's not available 
in betterC: https://run.dlang.io/is/WAjVuG

```D
extern(C):
import core.stdc.stdio;
import std.container;

void main()
{
     printf("hello, world\n");
     Array!int ai;
     ai ~= 1;
}

/* Compiler output:
/dlang/dmd/linux/bin64/../../src/druntime/import/core/internal/array/
onstruction.d(207): Error: cannot use try-catch statements with -betterC
/dlang/dmd/linux/bin64/../../src/phobos/std/container/array.d(151): Error:
template instance `core.internal.array.construction._d_arraysetctor!
const(Array!int)[], const(Array!int))` error instantiating
/dlang/dmd/linux/bin64/../../src/phobos/std/container/array.d(244):       
instantiated from here: `RangeT!(const(Array!int))`
/dlang/dmd/linux/bin64/../../src/phobos/std/container/array.d(633):       
instantiated from here: `RangeT!(Array!int)`
onlineapp.d(8):        instantiated from here: `Array!int`
/dlang/dmd/linux/bin64/../../src/druntime/import/core/internal/array/
onstruction.d(207): Error: cannot use try-catch statements with -betterC
/dlang/dmd/linux/bin64/../../src/phobos/std/container/array.d(151): Error:
template instance `core.internal.array.construction._d_arraysetctor!(imm
table(Array!int)[], immutable(Array!int))` error instantiating
/dlang/dmd/linux/bin64/../../src/phobos/std/container/array.d(639):       
instantiated from here: `RangeT!(immutable(Array!int))`
onlineapp.d(8):        instantiated from here: `Array!int`
*/
```

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

Yeah that is to be expected, things working in -betterC from 
druntime/phobos is the exception not the rule.

Due to assumptions about what is available.

Jonathan M Davis <newsgroup.d jmdavisprog.com> writes:

On Monday, September 18, 2023 10:02:00 PM MDT Ki Rill via Digitalmars-d wrote:
 I've been trying out std containers. Checked Phobos code - all
 seems to be  nogc. Good. Then I try out this and it fails because
 something throws in array construction and that's not available
 in betterC: https://run.dlang.io/is/WAjVuG

 ```D
 extern(C):
 import core.stdc.stdio;
 import std.container;

 void main()
 {
      printf("hello, world\n");
      Array!int ai;
      ai ~= 1;
 }

 /* Compiler output:
 /dlang/dmd/linux/bin64/../../src/druntime/import/core/internal/array/constru
 ction.d(207): Error: cannot use try-catch statements with -betterC
 /dlang/dmd/linux/bin64/../../src/phobos/std/container/array.d(151): Error:
 template instance
 `core.internal.array.construction._d_arraysetctor!(const(Array!int)[],
 const(Array!int))` error instantiating
 /dlang/dmd/linux/bin64/../../src/phobos/std/container/array.d(244):
 instantiated from here: `RangeT!(const(Array!int))`
 /dlang/dmd/linux/bin64/../../src/phobos/std/container/array.d(633):
 instantiated from here: `RangeT!(Array!int)` onlineapp.d(8):
 instantiated from here: `Array!int`
 /dlang/dmd/linux/bin64/../../src/druntime/import/core/internal/array/constru
 ction.d(207): Error: cannot use try-catch statements with -betterC
 /dlang/dmd/linux/bin64/../../src/phobos/std/container/array.d(151): Error:
 template instance
 `core.internal.array.construction._d_arraysetctor!(immutable(Array!int)[],
 immutable(Array!int))` error instantiating
 /dlang/dmd/linux/bin64/../../src/phobos/std/container/array.d(639):
 instantiated from here: `RangeT!(immutable(Array!int))` onlineapp.d(8):
    instantiated from here: `Array!int`
 */
 ```

-betterC is really only intended to make it easier to port C code to D, and
it naturally reduces how much of D that you can use, because it involves not
using D's runtime.

On the other hand, Phobos in general has been designed with the idea that
you will be using the entire language. Some parts of it happen to work with
-betterC, but pretty much all of it was written before -betterC was even a
thing, so if it works with -betterC, it's basically by accident.

- Jonathan M Davis