Databases
StackOverflow2013
Postsdbo
POFunction pointers, design
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POFunction pointers, design
    primarykey
    data
    text
    <p>I am in a problem with a design question in C.</p> <p>Let's say that I have a pretty large amount of functions, with different argument count.</p> <p>POQ:</p> <pre><code>int print_one(int x) { printf("one: %d\n", x); return 1; } int print_three(int x, int y, int z) { printf("three: %d-%d-%d\n", x, y, z); return 3; } </code></pre> <p>Now, I want to connect some properties to these functions in a structure, so that I can manipulate them without knowing the exact function, including their parameter count (I might even call the structure interface)</p> <p>I tryd it like this, (&amp; I think is pretty wrong):</p> <pre><code>typedef int (*pfunc)(int c, ...); typedef struct _stroffunc { pfunc myfunction; int flags; int some_thing_count; int arguments[10]; int argumentcount; } stroffunc; int main() { stroffunc firststruct; firststruct.pfunc = (pfunc) print_two; firststruct.something_count = 101; arguments[0] = 102; argumentcount = 1; flag &amp;= SOME_SEXY_FLAG; // now I can call it, in a pretty ugly way ... however I want (with patially random results ofc) firststruct.pfunc(firststruct.arguments[0]); firststruct.pfunc(firststruct.arguments[0], 124, 11); firststruct.pfunc(1, firststruct.arguments[0], 124, 1, 1); } </code></pre> <p>I find this solution very ugly, &amp; I think (hope) that there is a better solution for calling &amp; and setting the function pointers.</p> <p>I'm just hoping, that I was clear enough ... NOTE: I didn't compile this code, but i compiled &amp; run a very similar one so the concepts are working. NOTE: pure C needed</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. This table or related slice is empty.
    1. USlerosQ
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    3. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POFunction pointers, design
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. POFunction pointers, design
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. POFunction pointers, design
      1. This table or related slice is empty.
      1. VTUpMod
    1. COCasting to a variadic function pointer and then calling the function through it leads to undefined behaviour. For a start, recall that the arguments to variadic functions undergo the *default argument promotions*, which is really going to screw things up.
      singulars
      1. POFunction pointers, design
      1. USOliver Charlesworth
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload