On Wednesday, 14 October 2020 at 20:15:39 UTC, Jack wrote:
What's the difference between:
import core.stdc.stdlib : malloc;
auto x = malloc(s)[0..s];
and
auto x = cast(T)malloc(s);
?
I have been using the last but I saw in some code examples,
like this[1] the first being used. What's the difference? in
the first one bounds checking is performed, giving an error
right away, right? whereas the cast would just turn the null
into the class reference and manual check need to be done
later. Is that the reason?
[1]:
https://wiki.dlang.org/Memory_Management#Explicit_Class_Instance_Allocation
The difference is that the first version gives you a `void[]`,
and the second version gives you a `T`. Neither version does any
bounds checking.
Generally, you'd use the first version if you don't yet know what
kind of object is going to be stored in the allocated memory (for
example, if you're writing an allocator[1]), and the second
version if you do know the type.
[1]
https://dlang.org/phobos/std_experimental_allocator_building_blocks.html
