pointer problems :(
Author
i have a <void *> that points to an array of std::string's.
i want to then have an array of pointers that are GetWordsPtr( <thestring> ); so i create a new array of pointer that point to structs which (in them) contain the string. ( dont worry about the function i have made this ).
how do i make an array of pointers? ( not fixed size (array size) )
i have to use <void *> because it points to a struct of the type that it is :/
eg.
typedef struct {
std::string r_word;
bool start;
bool end;
int wordsbefore;
void * bwords; //ptr to array of word's
int wordsafter;
void * awords; //ptr to array of word's
} word;
Why are you using void * in the first place?
Say, you want an array of your word struct:
Toolmaker
Say, you want an array of your word struct:
int length = 100; // Dynamic lengthword *array = new word[length]; // Allocate the arrayarray[0].r_word = "blah blah";// Clean up the arraydelete [] array; // Make note of the []. It tells the compiler you're deleting an arrayToolmaker
Author
thanks alot but i dont think you understand my question. I also dont think you realise how well i know C++.
anyway i worked it out. its really messy and looks like this
anyway i worked it out. its really messy and looks like this
if( words[curword].wordsbefore > 0 ) { i = 0; strptr = (string *) words[curword].bwords; word *tempword; word * tptr = new word [ words[curword].wordsbefore ]; while( i < words[curword].wordsbefore ) { theword = strptr; tempword = (word*) GetWordsPtr( theword ); tptr = *tempword; i++; } delete [] words[curword].bwords; words[curword].bwords = tptr;}
Quote:Original post by ErUs
typedef struct {
std::string r_word;
bool start;
bool end;
int wordsbefore;
void * bwords; //ptr to array of word's
int wordsafter;
void * awords; //ptr to array of word's
} word;
why not declare bwords and awords to be string *'s anyway?
if that is what they always are, why bother with void* s and casting?
Author
at first they are strings, while i am loading the whole database. Then i make them pointers to the other words ( because the other words have to be in memory first :) )
Author
i just realised something silly :(
-
word * tptr = new word [ words[curword].wordsbefore ];
-
i dont want to be allocating new memory :( i want to point to the words allready in the memory :(
what is the defualt type for a pointer? UINT?
-
word * tptr = new word [ words[curword].wordsbefore ];
-
i dont want to be allocating new memory :( i want to point to the words allready in the memory :(
what is the defualt type for a pointer? UINT?
Quote:Original post by ErUs
i just realised something silly :(
-
word * tptr = new word [ words[curword].wordsbefore ];
-
i dont want to be allocating new memory :( i want to point to the words allready in the memory :(
what is the defualt type for a pointer? UINT?
That made no sense what-so-ever. A pointer can be of any type, why UINT? UINT is an unsigned int, which isnt a pointer unless you make it UINT*.
Author
so how do i create an array of pointers ( not create memory for the things they point to ) and then change what they point to later?
so i only want to create memory for the size of the POINTER's. :S
so i only want to create memory for the size of the POINTER's. :S
Quote:Original post by ErUs
so how do i create an array of pointers ( not create memory for the things they point to ) and then change what they point to later?
so i only want to create memory for the size of the POINTER. :S
I beleive that made no sense what-so-ever either. I dont believe a pointer takes space, does it? W/e, the point is, I dont know about arrays. I would use a 'vector'. Like this(in my SDL engine):
...
std::vector m_Images;
...
...
m_Images.reserve(AMOUNT_OF_POINTERS_YOU_WISH_TO_RESERVE, NULL);
...
I beleive that will do the trick.
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