Getting Started with OpenCL


I’m just starting to explore OpenCL. I’ve found this tutorial - - and I’m having some troubles.

Here is my code from just the start of the tutorial:

#include <utility>
#define __NO_STD_VECTOR // Use cl::vector instead of STL version
#include <CL/cl.h>

#include <cstdio>
#include <cstdlib>
#include <fstream>
#include <iostream>
#include <string>
#include <iterator>

int main(void) {
    cl_int err;
    cl::vector< cl::Platform > platformList;
    return 0;

I had to change CL/cl.hpp (in the tutorial) to CL/cl.h (in my code) because I only have cl.h on my machine. When I try to compile this code, I get:

In function 'int main()':
error: 'cl' has not been declared
error: 'cl' has not been declared
error: 'platformList' was not declared in this scope
error: 'cl' has not been declared
warning: unused variable 'err'
||=== Build finished: 4 errors, 1 warnings ===|

I have added the OpenCL include path, library path and OpenCL library to my build settings.

I have been able to successfully compile and run the vector addition application found here: It appears that the code between the two applications are of different styles:

// From tutorial
// From vector addition application
cl_int ret = clGetPlatformIDs(1, &platform_id, &ret_num_platforms);

Are there two different versions of OpenCL? Any help on why I can’t compile the tutorial code would be greatly appreciated! Also, any other good resources or tutorials for starters would be appreciated as well!

One tutorial is using the C-language and the other is using the C++ language.

So it turns out I was missing the C++ bindings. I downloaded it here: and placed it in the include directory, then changed my code back to CL/cl.hpp.

Awesome, thanks for the reply!