I am playing around with C++ again, and I have the following line which is causing a warning from g++:

Code:
vector<string> v;
...
for(int i = 0; i < v.size(); i++) {
The warning is:
Code:
vec.cpp: In function ‘int main()’:
vec.cpp:16: warning: comparison between signed and unsigned integer expressions
What do I do to satisfy the compiler? I assume I would declare i in some way connected v?