Add one_context() method to distributed context and queue

Author: jszuppe

include/boost/compute/distributed/command_queue.hpp

@@ -181,6 +181,13 @@ class command_queue
         return m_queues[n].get_context();
     }
 
+    /// Returns true if all device command queues are in the same OpenCL
+    /// context.
+    bool one_context() const
+    {
+        return m_context.one_context();
+    }
+
     /// Returns nth context from command queue's distributed context.
     ::boost::compute::device get_device(size_t n) const
     {

include/boost/compute/distributed/context.hpp

@@ -147,6 +147,16 @@ class context
         return m_contexts[n];
     }
 
+    /// Returns true if all contexts are in fact the same OpenCL context.
+    bool one_context() const
+    {
+        bool one_context = false;
+        for(size_t i = 0; i < m_contexts.size(); i++) {
+            one_context == one_context && (m_contexts[0] == m_contexts[i]);
+        }
+        return one_context;
+    }
+
     /// Returns information about nth context.
     template<class T>
     T get_info(size_t n, cl_context_info info) const