Re: [PATCH v2 3/8] qnum: QNumValue type for QNum value literals

[Markus Armbruster]

Eduardo Habkost <ehabkost@redhat.com> writes:

> On Fri, Nov 20, 2020 at 06:29:16AM +0100, Markus Armbruster wrote:
[...]
>> When the structure of a data type is to be kept away from its users, I
>> prefer to keep it out of the public header, so the compiler enforces the
>> encapsulation.
>
> I prefer that too, except that it is impossible when users of the
> API need the compiler to know the struct size.

There are cases where the structure of a data type should be
encapsulated, yet its size must be made known for performance (avoid
dynamic memory allocation and pointer chasing).

Need for encapsulation correlates with complex algorithms and data
structures.  The cost of dynamic allocation is often in the noise then.