New child language - (Function member address (structure))

[Imadatobanisa]

Oh, the hell?

STRCPY :

char string[100];
strcpy(string, "sdklfklsdfsd");

strcpy(string,string); //works OK 

STRCAT :

char string[100];
strcpy(string, "sdklfklsdfsd");

strcat(string,string); //Crash!!!! 

I see both two functions have the same syntax : (char*, const char*), but why does it crash? I completely have no idea.... :(

[L B]

Have you checked their requirements about source and target overlaps?

Also, don't use char arrays.

[Imadatobanisa]

Thanks L B! These must be a hidden error at somewhere in the function STRCAT.
Because also the default C++ code cannot solve this, and the returning value most likely is undefined. Just call it "UNDEFINED BEHAVIOR"


NEW TYPE-CAST!!!! Users now can use and apply type-cast directly for a value by using the form looks like : int(...); char(...); unsigned int(...);. As you can see this looks like a function, and I used this tweak to make this.
NOTE : Still useless if you write (int)(10 * 22.2) //It should be a function

double d = 100;
int m = int(d = modf(87.55, &d));

At least in my opinion it's better than :

int m = [int](d = modf(87.55, &d));

I have no idea should I remove the ugly bracket [] form? Any idea or suggestion?

[EssGeEich]

Jackson Marie wrote:

These must be a hidden error at somewhere in the function STRCAT.
Because also the default C++ code cannot solve this, and the returning value most likely is undefined. Just call it "UNDEFINED BEHAVIOR"

Oh, god, please ban.

Let me, oh, let me call EssGeEich::~EssGeEich();

[Imadatobanisa]

...The next step is POINTER. It's also the most difficult challenge. Any idea if I'm going to make a new pointer structure?

EssGeEich - What? My interpreter currently doesn't support this.

[EssGeEich]

Jackson Marie wrote:

EssGeEich - What? My interpreter currently doesn't support this.

You don't understand things on the fly, do you?

The strcat crash is NOT undefined behaviour, WHAT does make you think it is Undefined Behaviour?

If you care to read L B's post:

L B wrote:

Have you checked their requirements about SOURCE AND TARGET OVERLAPS?

I hope it was clear enough~ This is becoming kinda stressing - And -

Jackson Marie wrote:

Any idea if I'm going to make a new pointer structure?

Huh?

[Imadatobanisa]

Oh I'm sorry, there was a lot of things and actually I was very confused because I only tried to call strcat. More crazily, I tried to figure out every assembly code and made a similar function strcat. The function works fine, then why does the standard function crashs? So just a few doubt questions. :)

And about pointer, probably I'm not going to make a whole structure for pointers, but I have an idea...

How to convert a pointer to a r-value?

[L B]

http://www.cplusplus.com/reference/cstring/strcat/

strcat wrote:

destination and source shall not overlap.

This means that the first parameter cannot be in any way similar to the second, or it will crash. The fact that it doesn't work is defined right there in black and white.

You can't expect someone without legs to be able to run and jump just because their twin brother can.

[Imadatobanisa]

Wow, I figured out why the function crashs. :)

If you call the function strcat like this, the possible cause : At beggining, the function replaces the terminator null character with the first character of the character array. Then most likely the program will enter an infinite loop - only trying to search the null character (actually the null character has been replaced before). The null character (or the end of string) is never met or reached because both the length of the destination and source string are continuously growing up and up. Finally it causes "overflow". And a crash error begins!!!

Thank you L B, at least you are very smart!

[EssGeEich]

Yeah, that's the reason. About the question above, you mean dereferencing it? you use *pointer for that.

[chrisname]

Don't do it EssGeEich, you have so much to stay in scope for!

[EssGeEich]

chrisname wrote:

Don't do it EssGeEich, you have so much to stay in scope for!

Someone deleted my pointer, but I was on the stack! What's gonna happen to me now? D:

[Script Coder]

EssGeEich wrote:

Someone deleted my pointer, but I was on the stack! What's gonna happen to me now?

hope that some idiot noob makes some horribly incorrect code and saves you

[Imadatobanisa]

Pointless, My question is : How to convert a pointer value itself to a r-value (not about dereferencing a pointer)

And, which is better?

double d1 = double(100);
double d2 = [double]100;
double d3 = double(int(sqrt(125.00)));
double d4 = [double]([int]sqrt(125.00));

[EssGeEich]

Isn't it a rvalue already? Show some code and what you mean.

[Imadatobanisa]

double abc;
double *lpftemp = &abc;

int pointer_value = (int)lpftemp;

[EssGeEich]

And what's wrong?

[Imadatobanisa]

int pointer_value = (int)lpftemp;

The compiler generated a compling error.
It says : "cannot convert double* to int" :(

[Coder7777]

It says : "cannot convert double* to int" :(

Sigh...

Keep working on it Jackson but really I do think you need a little bit more experience to do a interpreter I think that is what your doing atleast

[EssGeEich]

This doesn't mean the pointer isn't a lvalue. Anyways are you sure your error shows up with the code you posted? Typecasting enum types always works - and a pointer is a number.