How do I know when a variable is accessed within my code?

Question

I'm using VS2008 to write a program. There's one specific line in my code that causes a numerical error. It is:

    Qp[j] = (Cp - Cm)/(Bp + Bm);

Qp is a std::vector. When I comment this line out, the numerical error disappears. I am going through my code line by line to find all the places that access Qp[j]. I was wondering if there was a feature in VS2008 or a linux program that wraps around the executable that can identify every line of code that reads from that section of memory (the specific element in the vector)?

I tried searching online but the keywords I used brought up results relating to global variables.

--- EDIT

Hi all. To those have responded, thank you. Just to clarify my question:

Imagine I have a vector with 5 elements. I'd like to know all the places in my code that use the value stored in element 3 at any point in time during execution. Is there an easy way to do this?

Answer 1

I am not sure if I understand you correctly, but if you comment out that line and the code works then maybe the problem is that line, and you don't need to check others lines.

Maybe in your case you get in the situation where Bp+Bm = 0 (division by zero error).

Answer 2

Qp可能没有索引j那么多的元素，检查Qp的大小。