How Do I: Nested struct

Hi guys, I have a little bit problem with my code. I had declare a pointer which is member to a nested structure. I pointed it to a string where the string is also located in the nested structure. But when I want to initialize the pointer with a constant string in main(), suddenly when I run it I get 'processor fault' but no warning or even error occur when I compile it.

//microsoft visual C++ 2010
#include<iostream>
#include<string>
using namespace std;

struct tagIF
{
	string binary;

	struct tagEA	//nested struct
	{
		string reg,mode;
	}EA,*pEA;
};

struct tagCLR : tagIF
{
	string DEF,B,W,L;

	tagCLR():DEF("01000010"), B("00"), W("01"), L("10") {}
}CLR;

void main()
{
	CLR.EA.mode="010";
	CLR.EA.reg="101";
	CLR.binary = CLR.DEF + CLR.B + CLR.EA.mode + CLR.EA.reg;
	cout<<hex<<strtol(&CLR.binary[0],0,2)<<"h\n\n";

	CLR.pEA->mode="010";		//compile: OK	 ,		run: processor fault
	CLR.pEA->reg="101";		//compile: OK	 ,		run: processor fault
	CLR.binary = CLR.DEF + CLR.B + CLR.pEA->mode + CLR.pEA->reg;
	cout<<hex<<strtol(&CLR.binary[0],0,2)<<"h\n\n";
}

Actually I want to use the 'this pointer'( -> ) to point at the string because I want my code looks logical and neater. I have tried to fix it with many times, search it on the internet, asking my friends, my lecturers. until present, I still fix it, but to no avail. Please show me how to fix it and tell me why.
~~I'm demanding your generosity.~~

Last edited on

Gaminic (1621)

Well, for one thing, I don't think you can nest structs that way. You can do this:

struct aStruct {
  // Members
}

struct bStruct {
   aStruct ab;
}

I'm actually confused that it compiled. Then again, I might be completely wrong.

mexists (15)

thanks, you mean like this right?

struct tagEA
{
        string reg,mode;
}/*EA, *pEA*/;
struct tagIF
{
	tagEA EA, *pEA;
	string binary;
};

if so, I still get the same error, sorry. I'm actually want to write the code that can fetch and assign the data in struct like this:

expression1.expression2->expression3;

so, any suggestion? do I need to change my code writing?

Last edited on

Gaminic (1621)

I think line 30 in your first post needs CLR.pEA between brackets. After all, that's the entire name for the pointer. Try (CLR.pEA)->mode ....

But, to be perfectly honest, I find nesting pointer structs very confusing.

Nisheeth (545)

What is the error you are getting?

mexists (15)

thanks Gaminic,

This is the first time you encounter nesting structure, right?

it's OK right now I have found the way how to fix it!!!

//this is Gaminic style
struct tagEA
{
	string reg,mode;
}EA,*pEA;

struct tagIF
{
	tagEA EA,*pEA;

	string binary;

	tagIF():pEA(&EA){}
};

or like this...

//this is my style
struct tagIF
{
	string binary;

	struct tagEA	//nested struct
	{
		string reg,mode;
	}EA,*pEA;

	tagIF():pEA(new tagEA) {}
};

Thanks friend, you give me a good inspiration... :)

mexists (15)

It's fine Nisheeth, problem has solved, thanks. :)

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How Do I: Nested struct