[SOLVED] c++ enum trouble

[chris200x9]

Hi I'm writing a dope wars clone and I am having trouble with enum I've enumed drugs like weed and crack so I can keep track of them like drugs[weed] but now I'm having trouble though with a check if they have 0 of a drug they are trying to sell the user puts in a choice then I see if drugs[choice] == 0. but I keep getting the error
no match for 'operator[]' in '((Guy*)this)->Guy::drugs[choice]'

[dwhitney67]

I (we) have no idea how you declared 'drugs', thus I cannot tell if it is an array, a vector, or something else.

You may want to consider posting some more code.

P.S. Why are you prefacing 'drugs' with 'Guy::'. Is drugs a static object? And if it is, then there is no need for the 'this->'. You should also never have to cast the pointer of 'this' to anything. Something like this should suffice (if 'drugs' is an array, vector, etc):

this->drugs[choice];

[chris200x9]

hi, my code is

cout << "what would you like to sell?\n";
cin >> choice;
if ( drugs[choice] == 0)
{
cout << "you don't have any " << choice;
}


and I declared drug like this


enum drugs {
weed,
crack
};


and I have this a my private variable

int drugs[]



I am sorry for my bad design but I started and my design just kept getting worse as time went on, as a newbie I just want to get a *working* version and the worry about rewriting it cleaner.

[John164918a]

The enum type is only useful for specifying names of things within the source code. That is to say if you want to be able to type and then print "heroin" for instance then you need to use strings. You could select your drug by typing in an integer which would then index an array of strings or a Drugs class.

Also in the first declaration you posted, drugs is an enumerative type. The next one should declare an instance of drugs_instance_with_a_different_name so it would look like



enum drugs drugs_instance_with_a_different_name;

The enum type drugs is not a variable and cannot be used to store information.
The instance of drugs can be used to store information.

Also, the compiler just told you you cant index into an enum like you can an array.

[chris200x9]

thanx! so your basically saying I would need to do something like this: http://ubuntuforums.org/showthread.php?p=5544215#post5544215 correct?

[dwhitney67]

thanx! so your basically saying I would need to do something like this: http://ubuntuforums.org/showthread.php?p=5544215#post5544215 correct?

What was posted by John164918a is not entirely correct; there are cases where enumerated values are used as integer indexes into arrays (vectors, maps, etc).

You probably should consider writing test programs to augment your knowledge of the STL map before you start tinkering with your game application.

You should consider defining a structure to hold specific drug information that your game's drug dealer will need, and not just rely on the drug's name and quantity.

For example:


#include <map>
#include <string>

class DrugDealer
{
public:
...

private:
// Structure to add info for each type of drug available
//
struct DrugFact
{
unsigned int amountInStock;
std::string unitType; // "kilo", "keys", "grams", etc.
float costPerUnit;
};

// Handy-dandy typedefs (for those who do not like to type)
//
// The "key" of the STL map is the drug-name. The "value" is
// the a DrugFact structure.
//
typedef std::map< std::string, DrugFact > DrugStore;
typedef DrugStore::iterator DrugStoreIter;

// Declaration of class-member data drugs.
//
DrugStore m_drugs;
};

[chris200x9]

thanx! :D