C++: Structs slower to access than basic variables?

Question

I found some code that had \"optimization\" like this:

void somefunc(SomeStruct param){
    float x = param.x; // param.x and x are both floats. supposedly this          


        

Answer 1

When you specify a "simple" variable (not a struct/class) to be operated upon, the system only has to go to that place and fetch the data it wants.

But when you refer to a variable inside a struct or class, like A.B, the system needs to calculate where B is inside that area called A (because there may be other variables declared before it), and that calculation takes a bit more than the the more plain access described above.