Error Cannot Convert Parameter 1

I'm working on my own version of corewars and I've come to a halt. I get this error... list:

Code:

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D:\Programs\Projects\Corewars\main.cpp(19) : error C2446: '==' : no conversion from 'char *' to 'int'
        This conversion requires a reinterpret_cast, a C-style cast or function-style cast
D:\Programs\Projects\Corewars\main.cpp(19) : error C2040: '==' : 'int' differs in levels of indirection from 'char [3]'
D:\Programs\Projects\Corewars\main.cpp(19) : error C2446: '!=' : no conversion from 'char *' to 'int'
        This conversion requires a reinterpret_cast, a C-style cast or function-style cast
D:\Programs\Projects\Corewars\main.cpp(19) : error C2040: '!=' : 'int' differs in levels of indirection from 'char [3]'
D:\Programs\Projects\Corewars\main.cpp(24) : error C2446: '!=' : no conversion from 'char *' to 'int'
        This conversion requires a reinterpret_cast, a C-style cast or function-style cast
D:\Programs\Projects\Corewars\main.cpp(24) : error C2040: '!=' : 'int' differs in levels of indirection from 'char [3]'
D:\Programs\Projects\Corewars\main.cpp(24) : error C2446: '==' : no conversion from 'char *' to 'int'
        This conversion requires a reinterpret_cast, a C-style cast or function-style cast
D:\Programs\Projects\Corewars\main.cpp(24) : error C2040: '==' : 'int' differs in levels of indirection from 'char [3]'
D:\Programs\Projects\Corewars\main.cpp(43) : error C2664: 'class std::basic_istream<char,struct std::char_traits<char> > &__thiscall std::basic_istream<char,struct std::char_traits<char> >::get(char &)' : cannot convert parameter 1 from 'char *' to
'char &'
        A reference that is not to 'const' cannot be bound to a non-lvalue

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Edit: the newest code is in the next page.

>else if(first[lp]=="/0" && second[lp]!="/0")
String literals and char literals are not the same. The escape character is \, not /.

>else if(first[lp]!="/0" && second[lp]=="/0")
String literals and char literals are not the same. The escape character is \, not /.

Yah I tried changing that a while ago, though I changed it back. It doesn't do anything for the error messages.

Code:

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else if(first[lp]=="/0" && second[lp]!="/0")

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should probably be

Code:

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else if(first[lp]=='\0' && second[lp]!='\0')

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Not sure if

Code:

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data.get(*program[lp]);

---

is correct...

Not sure I understand why you need a for loop in charchech() ..

Theres a loop because I'm doing it letter by letter. The loop only continues if each character is the same.

But you have break; inside all of your if's so it will only run through your loop once, hence a bit meaningless.

I'm trying to make my own function instead of strcmp. That's the entire point of making that function!

explain more specifically what's wrong

what's wrong with this though?

Code:

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data.get(*program[lp]);

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i tried data.get(&program[lp]) which is what I thought it had to be, and it came up with an error, no error came up with the *. I don't understand what you mean by uninitialized memory.

You really should set your pointers to zero

Code:

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char * program[30] = {0};

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The problem with

Code:

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data.get(*program[lp]);

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is that you have not allocated any space for the pointers. You have only set aside memory to an array of pointers.

You probably need to do something like

Code:

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for(int lp=0;lp!=30;lp++)
{
  program[lp] = new char[15];
  data.get(*program[lp]);
  cout << *program[lp] << endl;
  // more code
}

---

Now the address stored in program[] will pointer to a memory space that can hold 15 char's. I picked the number 15 randomly btw.

program[lp] is a pointer to a character (and the pointer points to nothing, e.g. it's a random address in memory)

*program[lp] is the value of the character at that unknown address


char * program[30]; is an array of character pointers, but none of them point to actual strings. They just hold random memory locations. There are no strings, nor is there memory set aside for the strings.

ok... so what i did now was

Code:

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char* programs[30];
char proglist[30];

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then in main i put:

Code:

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for(int lp=0;lp!=30;lp++)
        {
                programs[lp]=&proglist[lp];
                data.get(*programs[lp]);
                if(charcheck(programs[lp]," ")==true)
                {
                        strcpy(programs[lp],"EMPTY SLOT");
                }
        }

---

the problem now is that i have to cast the variables... or so it says in the errors:

Code:

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D:\Programs\Projects\Corewars\main.cpp(20) : error C2446: '==' : no conversion from 'char *' to 'int'
        This conversion requires a reinterpret_cast, a C-style cast or function-style cast

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(just one of the errors)

i dun know where it's trying to convert from a char to an int though.

nm... i never knew there was a difference between ' and "

now though, theres an error:

Code:

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D:\Programs\Projects\Corewars\main.cpp(50) : error C2664: 'charcheck' : cannot convert parameter 1 from 'char *[21]' to 'char *'
        Types pointed to are unrelated; conversion requires reinterpret_cast, C-style cast or function-style cast

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i've tried making char* first to char* first[21], but that doesn't make a difference. btw, here's the new code.

No, that's to easy... besides how will I learn pointers if I don't use them.

This thread is hilarious!!!!!!!!!!

I'm sure this has all been pointed out already, but here's another try.

> for(int lp=0;lp!=30;lp++)
This should be:
for(int lp=0;lp<30;lp++)

> data.get(*programs[lp]);
Try getline() and take off the star:
data.getline(programs[lp],21);

> strcpy(programs[lp],&"EMPTYSLOT ");
This should be:
strcpy(programs[lp],"EMPTYSLOT ");

> cout << *programs[1];

This should be:
cout << programs[1];
Or if you want the first string:
cout << programs[0];

all of that's already in the program... and I dun want getline, I'm doing word by word not line by line. Nothing has been solved.

Since nothing here seems to be helping you maybe look at this link it helped me to understand pointers...

I haven't seen any problems with my POINTERS THAT'S THE PROBLEM... FWOIIII... sorry, excuse my outburst. But seriously, i know pointers, i just don't know what's wrong, i never stated that my problem was with my pointers, I've done everything you've told me to and it hasn't helped.

edit: so I'm going to erase anything having to do with that god damn variable and I'm going to start from god damn scratch.

seriously, it's good to try challenging things to help you learn, but I think you're out of your depth on this one Dr. Droid.
You don't seem prepared to listen to people's advice anyway

Why don't you post your code (without ANY type casts), highlight each line (use [ color=red ] and [ /color ] tags to highlight a line) that gives a compilation error, and explain in words what each variable is supposed to be and what the goal of the program is.

Without knowing what you're trying to accomplish, how are we to know how to advise? For example:

char* programs[30][21];

This creates 630 pointers (presumably for strings of some kind) but allocates no memory for the strings themselves. Were you trying to allocate memory for 30 strings that are 21 characters long? That isn't what happened.

I've narrowed all of the errors down to mainly this:

Code:

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&data.get(programs[lp]);

&data.get(programs[lp],20);

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with and without the & before data. And about that other stuff was; how else was I going to practice pointers :p .

Quote:

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seriously, it's good to try challenging things to help you learn, but I think you're out of your depth on this one Dr. Droid.
You don't seem prepared to listen to people's advice anyway

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what makes you think that? I've tried everything that's been posted here. Despite what you may think I have, and even read that thing on pointers. I understand pointers in concept, and I think I know them in syntax... I've tried going through it to make sure there was a pointer, "pointee", a refrence etc.

Heres the code now:

Code:

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#include <iostream>
#include <fstream>
#include <conio.h>

using namespace std;

char proglist[31][21];
char (*programs)[31][21];

bool charcheck(char* first, char* second)
{
        bool success=true;
        int lp=0;
        for(;;)
        {
                if(first[lp]!=second[lp])
                {       
                        success=false;
                        break;
                }
                else if(first[lp]=='\0' && second[lp]!='\0')
                {
                        success=false;
                        break;
                }
                else if(first[lp]!='\0'&& second[lp]=='\0')
                {
                        success=false;
                        break;
                }
                else if(success==true && first[lp]=='\0' && second[lp]=='\0')
                {
                        break;
                }
                lp++;
        }
        return success;
}

int main()
{
        programs=&proglist;
        ifstream data("proglist.txt");
        for(int lp=0;lp<=30;lp++)
        {
                &data.get(programs[lp][0],20);
                if(charcheck(programs[lp][0]," ")==true)
                {
                        cout << "test";
                        strcpy(programs[lp][0],&"EMPTYSLOT ");
                }
        }
        data.close();
        cout << programs[1];
        getch();
        return 0;
}

---

With that, now I'm starting to get that it's performing illegal operations.

Edit:
COREWARS caused an invalid page fault in
module COREWARS.EXE at 0167:00404899.
Registers:
EAX=006bfdb8 CS=0167 EIP=00404899 EFLGS=00010246
EBX=005b0000 SS=016f ESP=006bfc04 EBP=006bfc94
ECX=0048111f DS=016f ESI=8196900c FS=20e7
EDX=006bfdb8 ES=016f EDI=006bfc84 GS=0000
Bytes at CS:EIP:
c6 01 00 8b 45 ec 8b 4d f4 64 89 0d 00 00 00 00
Stack dump:
006bfcf8 8196900c 005b0000 cccccccc cccccccc cccccccc cccccccc cccccccc cccccccc cccccccc cccccccc cccccccc cccccccc cccccccc cccccccc cccccccc

Edit2: BTW, i changed the latest sourcecode on page 2.

I'll echo what Salem said above.
Please describe in words what you want to happen. For instance, do you want to read the file char by char and place a pointer to each char or line by line or ... ?
Also please add part or all of the file "proglist".

Well, I used error flagging and found that it got all the way to here and then crashed.

for(int lp=0;lp<=30;lp++)
{
&data.get(programs[lp][0],20);
if(charcheck(programs[lp][0]," ")==true)
{
cout << "test";
strcpy(programs[lp][0],&"EMPTYSLOT ");
}
HERE
}
data.close();

edit: and this is the file... btw, I'm changing the code on page two again.

Code:

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this is a test

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Lol, i plan on changing the file once I get everythign running. Basically what I'm doing is loading a file that lists words, I'm loading thoughs words into an array(proglist) which I am pointing to with *program.

Quote:

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Basically what I'm doing is loading a file that lists words, I'm loading thoughs words into an array(proglist) which I am pointing to with *program.

---

A bit vauge description.

If the contest of your file is

Code:

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this is a test

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Do you want one pointer to "this", another pointer to "is" etc... or do you want one pointer to 't' then another to 'h' and 'i' and 's' etc ? Im still not totally getting this...

I loop through the array, that part of the array takes this, the next part of the array takes is the next part takes a and the next part takes test. Before all of that I create a pointer and the array, then I make a refrence from the pointer to the array.

Quote:

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you repeatedly make the same mistakes and basically ignore everything everyone says

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I just reread the entire thread for the 3rd or 4rth time and I've done everything you've told me to except forget about the pointers and do it another way.

take it easy on the little guy. he's just a kid :D

Code:

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char (*programs)[31][21];

---

Can you please explain what this does ?

Then explain what this does ?

Code:

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&data.get(programs[lp][0],20);

---

get method

Im finding this whole thing abit hard to grasp...

Quote:

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take it easy on the little guy. he's just a kid

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lmfao


char (*programs)[31][21];
this allocates a pointer for an array.

this loads each word(divided by spaces) of up to 20 characters into the beginning of each array part.

after that(not shown here) i check to see if it's blank if it is, then i make that part of the array "EMPTYSLOT ".

How's that?

This is your answer

Quote:

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char (*programs)[31][21];
this allocates a pointer for an array.

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This is what cat wrote earlier in this thread

Quote:

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char* programs[30][21];

This creates 630 pointers (presumably for strings of some kind) but allocates no memory for the strings themselves. Were you trying to allocate memory for 30 strings that are 21 characters long? That isn't what happened.

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I dont think you understand pointers properly.

Quote:

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The keyword new is used to initialize pointers with memory from free store (a section of memory available to all programs). The syntax looks like the example:

Example:
int *ptr = new int;

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Taken from pointer tutorial on this site.

this is how i created the array/pointer

Code:

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char proglist[30][21];
char (*programs)[30];

---

and I try to allocate space like this...

Code:

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for(int lp=0;lp<=21;lp++)
        {
                programs[lp]=new char[21];
        }

---

I get errors saying that: cannot convert from 'char *' to 'char[21]' for the line when i allocate the space.

This should work ..

Code:

---

int main()
{
    char proglist[30][21];
    char *programs[30];
   
    for(int lp=0;lp<=21;lp++)
    {
      programs[lp]=new char[21];
    }

    system("PAUSE");
    return 0;
}

---

Code:

---

int main()
{
        char proglist[31][21];
        char *programs[31];
        for(int lp=0;lp<=30;lp++)
        {
                programs[lp]=new char[21];
        }
        programs=&proglist;
    ifstream data("proglist.txt");
        for(lp=0;lp<=30;lp++)
        {
                data.get(programs[lp], " ");
                if(charcheck(programs[lp][0]," ")==true)
                {
                        cout << programs[1];
                        strcpy(programs[lp][0],&"EMPTYSLOT ");
                }
        }
        data.close();
        cout << programs[1];
        getch();
        return 0;
}

---

these are the errors(same problem, can't convert):

Code:

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D:\Programs\Projects\Corewars\main.cpp(45) : error C2440: '=' : cannot convert from 'char (*)[31][21]' to 'char *[31]'
        There are no conversions to array types, although there are conversions to references or pointers to arrays
D:\Programs\Projects\Corewars\main.cpp(49) : error C2664: 'class std::basic_istream<char,struct std::char_traits<char> > &__thiscall std::basic_istream<char,struct std::char_traits<char> >::get(char *,int)' : cannot convert parameter 2 from 'char [2
]' to 'int'
        This conversion requires a reinterpret_cast, a C-style cast or function-style cast
D:\Programs\Projects\Corewars\main.cpp(50) : error C2664: 'charcheck' : cannot convert parameter 1 from 'char' to 'char *'
        Conversion from integral type to pointer type requires reinterpret_cast, C-style cast or function-style cast
D:\Programs\Projects\Corewars\main.cpp(53) : error C2664: 'strcpy' : cannot convert parameter 1 from 'char' to 'char *'
        Conversion from integral type to pointer type requires reinterpret_cast, C-style cast or function-style cast
Error executing cl.exe.

Corewars.exe - 4 error(s), 0 warning(s)

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just looking at that part of your code, this works for me:

Code:

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int main()
{
        //char proglist[31][21];
        char *programs[31];
        for(int lp=0;lp<=30;lp++)
        {
                programs[lp]=new char;
        }
    programs[1]="hhh";
    ifstream data("proglist.txt");

        cout << programs[1];
 int x;
 cin>>x;
        return 0;
}

---

Try this then...

Code:

---

int main()
{
  char *programs[5];
  ifstream data("proglist.txt");
  for(int lp=0;lp<=5;lp++)
  {
    cout << "programs["<<lp << "] points to : ";               
    programs[lp]=new char[21];         
    data.getline(programs[lp], 20, ' ');
    cout << programs[lp] << endl;
  }
       
  for (int x=0; x <= 5; x++)
  delete programs[x];       
       
  delete[] programs;
  system("PAUSE");
  return 0;
}

---

I get the same errors as before... could this be a compiler problem after 4 pages?

Btw, sorry, I had to go to walmart that was like 10 miles away

edit: waaaait... hold on

Now the program crashes before I can output anything, heres the updated code, fully commented and organized:

Code:

---

int main()
{
        //Load the file proglist under the name data
        ifstream data("proglist.txt");

        //Create then allocate space to the pointer programs
        //Looping through each individual piece of the array
        char *programs[30];
        for(int lp=0;lp<=30;lp++)
        {
                programs[lp]=new char[20];
        }

        //Loop through each peace of the array and load the next word in data to it
        //Then close the file
        for(lp=0;lp<=30;lp++)
        {
                data.get(programs[lp],20,' ');
                //Print some parts of the array
                cout << "Programs[" << lp << "] = " << programs[lp] << endl;
        }
        data.close();

        //Loop through and free up the space from the array and then
        //delete the array
        for (lp=0; lp <= 30; lp++)
        {
                delete programs[lp];       
        }
        delete[] programs;

        //Wait for a keystroke and then end
        getch();
        return 0;
}

---

I'm getting an Illegal operation.

laasunde you there? salem?

Watch his post count soar!

I wasn't necessarily referring to your knowledge of pointers before, just your knowledge in general, you clearly have no idea what-so-ever about this program. Try something simpler.

Not sure why you get an illegal operation maybe someone else can spot the problem.

I do however think you should change your code from

Code:

---

data.get(programs[lp],20,' ');

---

to

Code:

---

data.getline(programs[lp], 20, ' ');

---

it runs fine on my computer anyways.

You should try to comment out part of your code so that you can narrow down what code segment thats causing your problem. You could probably start with the middle for loop, just a guess...

I think I pointed it out earlier that it always crashes at the call of data.get(programs[lp],20,' ')

Use getline instead of get as laasunde suggested. Your illegal operation is from here, no doubt:

delete[] programs;

You're trying to delete memory that is not yours to delete.

rply to lightatdown: it crashes before it even gets to there at the call of geline.

I haven't studied this whole thread (or the one before it) completely, but just looking at the code you just posted, here is what you must do to get it working:
[list=1][*]Change char *programs[30]; to char *programs[31]; or change all of your loops to stop at < 30 instead of <= 30. This is your crash.[*]Remove delete [] *programs; That will cause a crash also. The programs array was not allocated with new.[*]When you loop through programs and delete the char* strings, you must use delete [] programs[lp]; That is because all 30 (or 31) entries in the programs array are char arrays allocated with new [], so they must be deleted with delete [].[*]Now that your program doesn't crash, it doesn't do what you want because by using get you never get past the first word. You should probably do as others suggested with getline, but specifically for the code you last posted you can add the following:

Code:

---

char temp[2];
data.get(temp,2);

---

after you get the word into programs. I don't know why you need to do it that way, and I'm not sure that is the right way to fix your problem, but it worked for me.[/list=1]

ECCP1... It's made you laugh, it's made you cry... it's made you want to beat the living $$$$ out of drdroid.... and finally as the last episode comes to an end... you'll be guessing until the end.

Ok, here goes... the last problem was... ::drum rooolll:: a couple things... the delete couldn't delete an empty char, it seemed to have a problem with that... and the loops were to big... besides destroying them... after page 3.5 the problem was pretty much solved...

The... end....

?

edit: but theres one.. major TWIST!!! SOMEONE MUST DIE!!!!
edit: LOOK OUT BEHIND YOU!!! ::screams:: ::bang:: NOOOOO!!!!
::sad piano music plays in the background... credits roll::

Thanks Salem, Lasunde, Jlou, Lightatdawn and Cat... this has really made me look back at everything to learn every detail... not that I'm going to drop this project... I learned alot... thanks again.

really.. this time...
THE END