Re: Threads across programming languages

Am 03.05.2024 um 17:01 schrieb Michael S:

On Fri, 3 May 2024 13:23:13 +0200
Bonita Montero <Bonita.Montero@gmail.com> wrote:
 

Am 03.05.2024 um 11:18 schrieb David Brown:

On 03/05/2024 09:58, Bonita Montero wrote:

Am 03.05.2024 um 09:38 schrieb David Brown:
 

No it is not.  C-style functions (or C++ functions for that
matter) are not objects, and do not have calling operators.
Built-in operators do not belong to a type, in the way that class
operators do.

>
You can assign a C-style function pointer to an auto
function-object.

>
A C-style function /pointer/ is an object.  A C-style /function/ is
not. Do you understand the difference?

>
Practically there isn't a difference.
>

 For C, I agree, mostly because C has no nested functions.
For C++ (after C++11) I am less sure, because of lambdas with
non-empty captures.
 

Lambdas without captures can be casted to C function-pointers and those
lambdas have all the same function-pointer type if the signature of the
calling operator is the same.
A nice trick to enforce function-pointer casting is to apply the +-ope-
rator to a non-capturing lambda since the plus-operator can be applied
to all pointers (I can really recommend the book "C++ Lambda Story" for
such details); this makes it possible to make the function-pointer defi-
nition type-inferenced. Or if you want to create a function<>-object
from the lambda which is guaranteed not to allocate if you pass a C
function-pointer you can enforce that if you attach the +-sign to the
assigned lambda.