Should I use std::vector::at() in my code

Question

I noticed today that std::vector::at() is significantly slower than accessing values with square brackets []. According to the doc .at() i

Answer 1

Assuming your not using exceptions as some sort of signal-system, the difference is that vector::at() will ALWAYS throw an exception when you try to access an index out of bounds. vector::operator[] might either return an undefined value OR throw an access violation exception (or crash).