How can I know the actual bytes read in a file read

I have a file open for binary read as follow

Code:

---

ifstream fin(inFileName, ios::in | ios::binary);
fin.read(read_buffer, sizeof read_buffer);

---

Is there any way for me to know how many bytes were actually read? Suppose I am on my final read of the file and the number of bytes left is smaller than the size of my read_buffer, I want to know how many bytes of new data I read into the buffer. I thought fin.read() would return an int of number of bytes read but it doesn't. Thanks in advance.

istream::read() returns the stream. You probably want istream::readsome().