[messe]

> C has no pattern for breaking out of multiple for loops at the same time. Other languages like Java and JavaScript introduced "break label;" to handle this edge case. goto is perfectly acceptable to break out of multiple loops.

Yeah, that's not what it does. The code looks like this:

    if (pgeom->Intersect(pentlist[i]->m_parts[j].pPhysGeomProxy->pGeom, gwd,gwd+1, &ip, pcontacts)) {
            got_unproj:
            if (dirUnproj.len2()==0) dirUnproj = pcontacts[0].dir;
            t = pcontacts[0].t;     // lock should be released after reading t
            return t;
    }       
    for(int ipart=1;ipart<m_nParts;ipart++) if (m_parts[ipart].flagsCollider & pentlist[i]->m_parts[j].flags) {
            gwd[2].R = Matrix33(qrot); 
            gwd[2].offset = pos + qrot*m_parts[ipart].pos;
            gwd[2].scale = m_parts[ipart].scale;
            gwd[2].v = -dirUnproj;
            if (m_parts[ipart].pPhysGeomProxy->pGeom->Intersect(pentlist[i]->m_parts[j].pPhysGeomProxy->pGeom, gwd+2,gwd+1, &ip, pcontacts))
                    goto got_unproj;
            }
    }

Notice (a) the if statement on the same line as the for loop, and (b) the fact that the goto jumps out of a conditional inside a for loop inside of a conditional into a conditional just before the for loop.

EDIT: Just realised the poster is referring to a different function.

IMO this one is more horrifying.

[Jasper_]

That's in a different function, so I wasn't counting it, but sure. I mean, I would write it differently, but it's fairly readable. It's jumping to a common function epilogue once it finds something it can collide with. Seriously -- try reading through it rather than gawking at the goto.

[naikrovek]

It's funny watching people reply to you without knowing anything about your skill set and experience.

Jasper_ is the real deal, people.

[iforgotpassword]

I still don't know who he is, but just from the arguments brought up you can tell this guy has experience in this stuff.

Those blanket statements like "never use goto" and "always trust stl" generally make me wary. I started out with gwbasic once, writing horrible goto spaghetti code. When moving through Pascal and C I eventually learned the "never use goto" mantra and naively tried to follow it at all cost. After I while I eventually encountered the "breaking out of nested loops" problem and refrained from using goto since I didn't want to look like a complete dork. I think I ended up with a flag that was set in the inner loop and checked in the outer and a break in each loop. That's what you get from blindly following rules that others try to present you as god-given.

[teawrecks]

IMO it should be clear from the top of a for loop how many iterations it will run. A goto randomly inside the loop is akin to a side effect in a function. Sure it might be the easiest solution you can think of, and might even generate optimal code, but it's less readable and forces future maintainers to exert more effort to understand the code.

[iforgotpassword]

> IMO it should be clear from the top of a for loop how many iterations it will run.

How would you implement something simple like a lookup in an array? From this argument even a break in a normal for-loop would be bad since I wouldn't know anymore how many iterations it will take. So if you have a nested loop and a "goto end_outer_loop" that's perfectly fine.

[userbinator]

Either that code is misleadingly indented and you copied one more closing brace than necessary, or you omitted the opening brace for the last if's body (which contains a single goto).

[messe]

Good catch. I think I copied one more than necessary, and then messed up when trying to fix up the indentation for HN.