Determine size of dynamically allocated memory in C

Question

Is there a way in C to find out the size of dynamically allocated memory?

For example, after

char* p = malloc (100);

Is there

Answer 1

Like everyone else already said: No there isn't.

Also, I would always avoid all the vendor-specific functions here, because when you find that you really need to use them, that's generally a sign that you're doing it wrong. You should either store the size separately, or not have to know it at all. Using vendor functions is the quickest way to lose one of the main benefits of writing in C, portability.