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

Note: using _msize only works for memory allocated with calloc, malloc, etc. As stated on the Microsoft Documentation

The _msize function returns the size, in bytes, of the memory block allocated by a call to calloc, malloc, or realloc.

And will throw an exception otherwise.

https://docs.microsoft.com/en-us/cpp/c-runtime-library/reference/msize?view=vs-2019