Re: How to know how many bytes in buffer?

"Boki" <bokiteam@ms21.hinet.net> wrote in message
news:1149479689.179066.271380@y43g2000cwc.googlegroups.com


What sort of buffer is it? If it is a std::vector like

std::vector<int> vec;

you can use the capacity() member function and multiply it by sizeof(T),
where T is the type being stored (int in the example I gave).

If it is an array like

int buffer[] = {1,3,3,34,4};

you can use sizeof(buffer), but only in the scope in which the array is
declared. If the array name is passed to a function, then you cannot
retrieve the size from the array name within the function.

If the array is dynamically allocated

int *ptr = (int*)malloc(20);

then there is no standard way to retrieved the size of the buffer pointed
to. However, Microsoft offers an function that is an extension to the
Standard called _msize. This is only documented to work with malloc (and
calloc and realloc), but it also seems to work with new.

--
John Carson