enum pointer

[TucsonDon]

typedef struct
{
    uint8_t prow[10];
    uint8_t pcolumn[10];
    uint8_t min;
    uint8_t max;
    ModeSec_t name;
    ModeSec_t disp[6];
    PLCDMove lcd_add;
    PputsLCD lcd_dis;
    unsigned set :1;
}TextDisplayAdd_t;

I am using this structure for elements of a menu with ModeSec_t being enumeration type. I want to use a different list for a sub menu w/o having to declare a new structure and current list has 50 elements. What is the most efficient way to point to either list

 

[rjenkinsgb]

Separate the general typedef from the instance creation; eg.

typedef struct TextStruct
{
    uint8_t prow[10];
    uint8_t pcolumn[10];
    uint8_t min;
    uint8_t max;
    ModeSec_t name;
    ModeSec_t disp[6];
    PLCDMove lcd_add;
    PputsLCD lcd_dis;
    unsigned set :1;
};

TextStruct TextDisplayAdd_t;

TextStruct TextMenu_t

 

[TucsonDon]

rjenkinsgb thanks for the info. The issue that I have is ModeSec_t is a typedef'ed enum list. I want to change this to point to that list or another list w/o declaring another variable (i.e. the same variable for either list)

 

[rjenkinsgb]

A union with pointers to both types?

You could use a void pointer, but you would need to cast it to the correct type every time it was used anywhere.

 

[TucsonDon]

A union with pointers to both types?

You could use a void pointer, but you would need to cast it to the correct type every time it was used anywhere.

rjenkinsgb I am unsure how I need to do that, I know how to do a union, just not the way you suggest.

 

[rjenkinsgb]

Something like:

union uptr {
TextDisplayAdd_t * txtptr;
ModeSec_t * modptr;
};

uptr.txtptr and uptr.modptr

Same memory location, but the context tells the compiler which type of data is being addressed.

 

[TucsonDon]

Something like:

union uptr {
TextDisplayAdd_t * txtptr;
ModeSec_t * modptr;
};

uptr.txtptr and uptr.modptr

Same memory location, but the context tells the compiler which type of data is being addressed.

TextDisplayAdd_t is a structure type with ModeSec_t name and ModeSec_t disp[6] elements. ModeSec_t is an enumeration type. I want to make the array to point to ModeSec_t or another enumeration type.

 

[tumbleweed]

ModeSec_t is an enumeration type. I want to make the array to point to ModeSec_t or another enumeration type.

Not quite sure I follow you here, but you can't have a pointer to an enum type. You can have a pointer to a variable of type ModeSec_t, but not ModeSec_t itself.

An enum type is just another definition for an int, so it has no storage. In your structure above, 'name' and 'disp[6]' are just fancy names for integers.

 

[TucsonDon]

Not quite sure I follow you here, but you can't have a pointer to an enum type. You can have a pointer to a variable of type ModeSec_t, but not ModeSec_t itself.

An enum type is just another definition for an int, so it has no storage. In your structure above, 'name' and 'disp[6]' are just fancy names for integers.

tumbleweed thanks for the info