Hands-On GPU Programming with Python and CUDA

Using functors in Thrust

Let's see how we can use a concept known as functors in Thrust. In C++, a functor is a class or struct object that looks and acts like a function; this lets us use something that looks and acts like a function, but can hold some parameters that don't have to be set every time it is used.

Let's start a new Thrust program with the appropriate include statements, and use the standard namespace:

#include <thrust/host_vector.h>#include <thrust/device_vector.h>#include <iostream>using namespace std;

Now, let's set up a basic functor. We will use a struct to represent this, rather than class. This will be a weighted multiplication function, and we will store the weight in a float called w. We will make a constructor that ...