Typedefs inside classes

[Pelle Beckman]

Hi,

Reading X. Meng's post on embedded classes I came to
think of a similar problem I found myself having.

void GamestateToString(class GameApp::TGamestate);

class GameApp {
typedef enum {
STATE_1,
STATE_2
} TGamestate;

[...]
};

This won't compile since I'm not allowed to
define GamestateToString()'s arguments like
that. Why?

In fact, it seems like I can't access GameApp::TGamestate at all,
not even for simple variables, ie.

GameApp::TGamestate state;
state = STATE_1;

-- Pelle

 

[John Carson]

Hi,

Reading X. Meng's post on embedded classes I came to
think of a similar problem I found myself having.

void GamestateToString(class GameApp::TGamestate);

class GameApp {
typedef enum {
STATE_1,
STATE_2
} TGamestate;

[...]
};

This typedef is unnecessary --- a hangover from C. You can make it:

class GameApp {
enum TGamestate{
STATE_1,
STATE_2
};

[...]
};

This won't compile since I'm not allowed to
define GamestateToString()'s arguments like
that. Why?

You are doing three things wrong:

1. You should be declaring GamestateToString after, not before, the GameApp
class.

2. Anything in a class is private by default. You need to specify public:
before TGamestate.

3. You are using the wrong syntax for function parameters. Rather than

void GamestateToString(class GameApp::TGamestate);

try

void GamestateToString(GameApp::TGamestate state);

 

[Rolf Magnus]

Hi,

Reading X. Meng's post on embedded classes I came to
think of a similar problem I found myself having.

void GamestateToString(class GameApp::TGamestate);

class GameApp {
typedef enum {
STATE_1,
STATE_2
} TGamestate;

[...]
};

This won't compile since I'm not allowed to
define GamestateToString()'s arguments like
that. Why?

Because TGamestate is private in class GameApp, and because the class is
defined after the declaration of GamesateToString, so the compiler doesn't
know anything about GameApp::TGamestate yet.

In fact, it seems like I can't access GameApp::TGamestate at all,
not even for simple variables, ie.

GameApp::TGamestate state;
state = STATE_1;

What does "can't access" mean? What happens if you try?