Structs for C++ and Qt

just wondering if there is a set way of doing structs in qt. i have made structs before in the past using C, but im not too sure about using C++ to do it and to make it work with the Qt stuff. any idea's???

Try the same way as in C :)

Code:

---

struct Point {
  int x;
  int y;
};

---

BTW. Structs are treated by C++ as public classes, so you can add methods to them.

ah ok thankyou...whilst im on the subject of storage, would it be easier to have a 2-d array of booleans or an array of linked lists??how would i create a 2-d array of booleans anyway because ive never tried it before - even with C??

Quote:

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Originally Posted by wysota

Try the same way as in C :)

Code:

---

struct Point {
  int x;
  int y;
};

---

BTW. Structs are treated by C++ as public classes, so you can add methods to them.

---

Ah... so that explains why Fullmetalcoder can, in the "devqthighlighter.h" header of his "DevQt" project, use

Code:

---

class CodeBlock;
....
....
struct CodeBlock{
...
}

---

It compiles with a ton of warnings, an executable, but no errors. If I change the declaration to "struct CodeBlock;" and compile then I get a ton of errors and no executable.

Quote:

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Originally Posted by therealjag

ah ok thankyou...whilst im on the subject of storage, would it be easier to have a 2-d array of booleans or an array of linked lists??how would i create a 2-d array of booleans anyway because ive never tried it before - even with C??

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It depends. In general there are no such things as 2D arrays. How many bools do you need in each "row"? Maybe you could use bit fields?

Quote:

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It depends. In general there are no such things as 2D arrays. How many bools do you need in each "row"? Maybe you could use bit fields?

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well i'd probably need around 30 maximum but around 10 would do for now....what are bit fields though i have never used them before?

Then bitfields will do fine.

Code:

---

struct bfentry{
unsigned int 
  one:1,
  two:1,
  three:1,
  four:1,
//...
  thirtytwo:1;
}

---

The above structure occupies.... 4 bytes :) Making it an array is easy now;

Of course you can also use: std::vector< std::vector< bool > >

Dear All,
I've a similar problem, i need a global struct such as:

Code:

---

struct _Stxy1000{
	 double dY[1000];
	 double dX[1000];
}

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I've put the previous code in a .h file and the follow:

Code:

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struct _Stxy1000 _stxy1000;

---

in a .cpp file which include the .h as definition.
When i use the struct field members in a .cpp, the compiler rise up some problems, such as "multiple definition" of the _stxy1000 variable.
Do you think i should use extern in the declaration?
Could you please post a c-like code??
Thanks in advance.
Andrea

I think you should definitely end your structure definition with a semicolon.