return the span on pop

Author: paul-szczepanek-arm

platform/include/platform/CircularBuffer.h

@@ -263,15 +263,14 @@ class CircularBuffer {
     /**
      * Pop multiple elements from the buffer.
      *
-     * @param dest The array which will receive the elements.
+     * @param dest The span that contains the buffer that will be used to store the elements.
      *
-     * @return The number of elements popped.
+     * @return The span with the size set to number of elements popped using the buffer passed in as the parameter.
      */
-    CounterType pop(mbed::Span<T>& dest)
+    mbed::Span<T> pop(mbed::Span<T>& dest)
     {
         CounterType popped = pop(dest.data(), dest.size());
-        dest = mbed::make_Span(dest.data(), popped);
-        return popped;
+        return mbed::make_Span(dest.data(), popped);
     }
 
     /** Check if the buffer is empty.