Memory Alignment

[RoshanX]

hi all,

I have a block of memory, and I am storing arbitrary number of basic types ( floats, ints, chars, and char* ( strings )) in this block of memory.

--------------------------------------
| int | int | float .....
--------------------------------------

When I want to access these variables, I use a pointer to the first byte of this memory block and an index, something like this

eg. to access the second int,

 char* block_pointer = new char[1024];
 ...
 ...
 // to access the second int
 int second_int = *(block_pointer + sizeof(int));

my question is, would this approach produce undesired effects ( alignments problems )

[Ancient Dragon]

If the integers are not aligned on correct alignment boundry, asscess will be slower but the data should still be ok.

[Salem]

> my question is, would this approach produce undesired effects ( alignments problems )
Yes.
Maybe not immediately, but long term it is not a good approach.

Here's someone else who's managed to dig a pit for themselves
http://cboard.cprogramming.com/showthread.php?t=79516

[vangmor]

If you store the values as ints or floats or the correct type no...
//value = int type
*((int*)(block_pointer + sizeof(int))) = int_value;
//Next value = double...
*((double*)(block_pointer + 2*sizeof(int))) = double_value;
//...
int second_int = *((int*)(block_pointer + sizeof(int)));
double third_double = *((double*)(block_pointer + 2*sizeof(int)));

[Salem]

> *((double*)(block_pointer + 2*sizeof(int))) = double_value;
How does this solve anything?