CPP vector - what does it mean?

Question

What does mean this row of code? Allocating of memory for some data?

std::vector<float> points((F - E) / sizeof(float));

Thank you

Answer 1

From std::vector documentation ,

std::vector<float> points(n);

creates a vector of size n whose elements are of type float. That is, n is the size of the vector. So for example

std::vector<float> vec(5); //creates a vector(of size 5) of float

In your case n's value is given by the expression:

(F - E) / sizeof(float)

So the vector point in your case have (F - E) / sizeof(float) number of elements.