Inheritance Problem

[cush2187]

I have not used C++ in about a year and I was trying to get my project to use Inheritance. I have already created my header file that looks something like:

class Instructions // start class Instructions
{
public:
Instructions();
Instructions(const char*);
Instructions(Instructions*);
~Instructions();
const Instructions & operator = (const Instructions&);
friend ostream & operator << (ostream&, const Instructions&);
Instructions(vector<string> sendingVect);

virtual int foobar();
};

class LDI: public Instructions
{
protected:
double healthValue;

public:
LDI(LDI*);
LDI(int value);
};

class LD: public Instructions
{
protected:
double capacity;

public:
LD();
LD(LD*);
};

I also have Instructions.cpp file that has the correct Constructors for each class:

Instructions::Instructions()
{
return;
}

LDI::LDI(int valueTemp)
: Instructions()
{
value = valueTemp;
}


LD::LD()
: Instructions()
{
//capacity = sentCapacity;
}

So when I create an instance in main.cpp of Instruction nothing happens it works fine, but when I try to do:

LDI *test = new LDI();

inside main it gives me an error saying that LDI is not a type. I have also tried doing Instructions *test = new LDI(); I still get the same error. Does anyone know a good solution to this error?? Thanks for the help!

[laserlight]

I notice that LDI does not have a default constructor.

Please post your well indented code in [code][/code] bbcode tags. You should also post the exact error message.

[laasunde]

The code you provided should not compile, the variable 'value' is not defined.

LDI::LDI(int valueTemp)
: Instructions()
{
  value = valueTemp;
}

Please provide a proper example that demonstrates your problem using code tags.

[abhaykumar]

LDI *test = new LDI();
This will give linker error because LDI is inheritted from Instruction which has a virtual function foobar() only declared. You must define this function either in Instruction or LDI. It will work then.

[D_Drmmr]

class Instructions
{
public:
Instructions();
Instructions(const char*);
Instructions(Instructions*);
//...
};

That gives me shivers. A pointer to Instructions is implicitly castable to an instance of Instructions.

Did you copy-paste this code snippet from your actual code or did you just type it in manually? Please don't do the latter, cause it's a waste of time to have to correct typos.