Pointer casting and indirection is killing me!

Leviticus Cirrrealus Titanium · 2002-12-10T08:42:44

ok here''s the code.... void AddMember(Member **newMember) //in main() I plan to use the function like this: //Member *newMemberList = NULL; //newMemberList = (Member*)malloc(10 * sizeof(struct MemberData)); //AddMember(&newMemberList); //therefore i can add Members directly (hopefully) //Member == typedef struct MemberData { int tempInt = 0; static int memberposition = 1; char tempNumber[3] = {0}; char tempName[10] = {0}; if (numOfMembers > sizeOfList) ResizeDatabase(*newMember); ... } ///////////////////////////////////////////////// struct MemberData ** ResizeDatabase(Member **moreMembers) { int dbSize = 0; if (sizeOfList == MAX_DB_SIZE) printf("Sorry, database is full.\n"); else if ((sizeOfList + RESIZE_PADDING) > MAX_DB_SIZE){ dbSize = MAX_DB_SIZE - sizeOfList; moreMembers = (Member**)realloc(moreMembers, dbSize * sizeof(struct MemberData)); } else { dbSize = RESIZE_PADDING; moreMembers = (Member**)realloc(moreMembers, dbSize * sizeof(struct MemberData)); } sizeOfList += dbSize; return (moreMembers); } basically newMemberList is already pointing to newly reallocated memory. then i use AddMember to fill in the structs. but i want to automatically resize the array if i am going to go past the limit. it seems like all the pointer indirection is getting me confused. i look on MSDN for info on struct _iobuf... but i couldn''t find anything could someone help me. thanks. oh this is the error i''m getting: C:\Program Files\Microsoft Visual Studio\MyProjects\database\MemberList.cpp(76) : error C2664: ''ResizeDatabase'' : cannot convert parameter 1 from ''struct MemberData *'' to ''struct _iobuf *'' Types pointed to are unrelated; conversion requires reinterpret_cast, C-style cast or function-style cast Error executing cl.exe.

For Beginners

Started by Alpha_ProgDes December 10, 2002 02:44 AM

12 comments, last by Alpha_ProgDes 21 years, 11 months ago

Pepe

122

December 10, 2002 05:50 AM

(*Mack)->name = name;

because *Mack is a pointer to a Truck.

It''s the same as

(**Mack).name = name;

Alpha_ProgDes

Author

6,963

December 10, 2002 06:00 AM

last newbie/silly question of the night/day....

so this is legal also?

(*Mack)->name = name;

or should it be (*Mack).name = name; ??? so sorry for silly questions? this just confuses me so much.

Beginner in Game Development? Read here. And read here.

Pepe

122

December 10, 2002 06:12 AM

(*Mack).name = name; In what context? if Mack is an array of pointers to Truck it's correct. But then it will be more readable: Mack->name = name; The operators -> and [] are mere abbreviations (if aren't overloaded): x->y is for (*x).y and x is for *(x + i) edited because was fucking as italics [edited by - Pepe on December 10, 2002 7:33:12 AM]