Does declaring C++ variables const help or hurt performance?

Question

I understand the behavior of const-qualified data types. I am curious, though, if there is any performance gain or loss from over- or under-zealousness of quali

Answer 1

const is just there to help you catch errors at compile time. However since there's this thing called the const_cast you can always change the constness of any variable so the compiler really can't get away with optimizing anything away. (You can also have fun with c-style casts to get rid of constness which could make optimizations invalid.)