malloc error when trying to assign the returned pointer to a struct field

[rempas]

On Friday, 8 September 2023 at 16:02:36 UTC, Basile B. wrote:
>
> Could this be a problem of copy construction ?

I don't think so. The assertion seems to be violated when 
`malloc` is used. And when I assert the result in the `_ptr` 
field. Really weird...