rarg, memcpy is annoying

[jverkoey]

Rarg!!!

ok, i'm using memcpy to try and pull out some data from an array of unsigned chars.

the way i'm doing this is: i read data from a file and put it in to a dynamically allocated array of unsigned chars.

Then, when i need something out of it, i do a memcpy to get the data.

Now, the way i'm trying to do this is, the files themselves have a bunch of unsigned ints and floats in them, so i need to do a memcpy like so:

memcpy(floatVar, data, sizeof(float));

or something like that. But when i try and do that, it won't compile. So, then i add a (void*) to the beginning of floatVar, and it compiles fine, but when i run the program, it crashes........rarg!!!

anyone know how to copy memory over to a float variable?

or should i just do it the "old-fashioned" way and just do everything AS i'm reading in the file? (the reason I'm doing it this way is so that if the program crashes mid-read, it won't lose the file data....)

[adrianxw]

Is floatVar a pointer type? How about data? memcpy() wants addresses there.

[XSquared]

...rarg?

[jverkoey]

data is an unsigned char*

floatvar is a float

[jverkoey]

i tried that, but when i run the program, it crashes

[darksaidin]

Originally posted by jverkoey
i tried that, but when i run the program, it crashes

How did you "dynamically" allocate data ?

Did you create a normal array like a) byte data[iSomeSize] or is data a pointer to something like b)data= new byte[iSomeSize] ?

In both cases, &data[0] should work thanks to the smart [] operator. This also allows you to specify a position in data from where you want to read the float (assuming there is more than just 4 bytes in "data").