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Thank you everyone for offering to help! I will first try to duplicate the problem with a small example. If that doesn't work then I will zip up the full program and upload. Thanks again!

Well it's a bit complicated: the function pointer that points to either fn1 or fn2 is used inside another member function of the same class like this:

(this->*fnptr)()

and fn1 and fn2 actually...

Thank you! But I tried both

public:
MyClass(): fnptr(&MyClass::fn1){
...
}; and

public:
MyClass(): {
fnptr=&MyClass::fn1;

Another question: can the assignment be done in the constructor? (to initialize the pointer)

I tried it but kept getting core dump. :confused:

Thanks! So if I understand it correctly, when calling from mc1,

(this->*fnptr)()

calls

mc1.fn1

and

Wait! When calling the function pointer it is just calling the function pointer, not the actual function. So it's still not clear to me how
mc1.fn1 and
mc2.fn1 are distinguished. :confused: Does ...

Ah yes. Now I remember another thing the compiler wants me to do is

(this->*fnptr)(), not just
fnptr().

Thank you! :)

I have a class with member functions and a pointer like this:


class MyClass{
private:
typedef void(MyClass::*memFnPtr_t) ();
public:
memFnPtr_t fnptr;
void fn1();
void...

Thanks! Point well taken - I already fixed the code when VC++ did not do the "smart optimization" and exposed the bug. The exercise of looking at the assembly code was just to understand why g++...

Any NetBeans user out there that knows the trick? Thanks!

Hello all, Thank you very much for the comments. I learned a lot from this forum as always. Here is what I found:

Using the -S switch I let g++ produce assembly codes for each of the two...

First of all sorry for my stupid comment about g++ having a "bug". I know it is a well built tool.



I know the binaries are the same because I use BeyondCompare to do binary comparisons. When I...

Thanks for the comments about '/' vs '\\'.

Now I am still fascinated by the fact that g++ produced identical binaries from codes with different logic. So I made a small example project and tested...

A related question: There are two huge files "projectname.sdf" and "projectname-xxxxxx.ipch". Can they be disabled or deleted? Thanks!

Thanks! Does MSVC take mixture of '/' and '\\'?

I had a flawed function like this:


fn(){
char c;
if (runFirstTime){
#ifdef VC
c='\\';
#else
c='/';

Well I got a new laptop and the problem came back. I got a bunch of warnings and errors when the IDE tried to link the fltk library:


Update: I figured it out. The fltk library was compiled with...

I would like to rewrite something like

sprintf(str, "%d, %.1lf, %.3lf, %.2lf, ...", a, b, c, d, ....)
to something like

But is there a way to specify varying precision easily (there are about...

Does the speed depend on how many bits are shifted? For example would >>16 take longer than >>1 ? Just curious. Thanks!

Thanks again everyone! :)

Thank you both! How about integer multiplication vs. shift? For example <<2 vs. *4 ? Thanks!

Long time ago I heard that the speed of floating point multiplication is much faster than division. Is it still the case today? (On a not very powerful netbook) Thanks!

I have to move the multimap back into the class otherwise different instances of the class share the same multimap and interfere with one another. Now the code looks something like



class...

OK I hope I am getting close to the right track: failed to find the syntax to call std::mem_fun and confused by std::function and std::bind, I found this:...

Understood. Thank you very much!