Explicit specialization for empty TransferBuffer (for single frame transfers)

libuavcan/include/uavcan/internal/transport/transfer_buffer.hpp

@@ -335,7 +335,11 @@ class TransferBufferManager : public ITransferBufferManager, Noncopyable
 public:
     TransferBufferManager(IAllocator* allocator)
     : allocator_(allocator)
-    { }
+    {
+        assert(allocator);
+        StaticAssert<(MAX_BUF_SIZE > 0)>::check();
+        StaticAssert<(NUM_STATIC_BUFS > 0)>::check();
+    }
 
     ~TransferBufferManager()
     {
@@ -425,4 +429,31 @@ public:
     }
 };
 
+template <>
+class TransferBufferManager<0, 0> : public ITransferBufferManager
+{
+public:
+    TransferBufferManager(IAllocator* allocator)
+    {
+        (void)allocator;
+    }
+
+    TransferBufferBase* access(const TransferBufferManagerKey& key)
+    {
+        (void)key;
+        return NULL;
+    }
+
+    TransferBufferBase* create(const TransferBufferManagerKey& key)
+    {
+        (void)key;
+        return NULL;
+    }
+
+    void remove(const TransferBufferManagerKey& key)
+    {
+        (void)key;
+    }
+};
+
 }

libuavcan/test/transport/transfer_buffer.cpp

@@ -338,3 +338,11 @@ TEST(TransferBufferManager, Basic)
     mgr.reset();
     ASSERT_EQ(0, pool.getNumUsedBlocks());
 }
+
+
+TEST(TransferBufferManager, EmptySpecialization)
+{
+    uavcan::TransferBufferManager<0, 0> mgr(NULL);
+    (void)mgr;
+    ASSERT_GE(sizeof(void*), sizeof(mgr));
+}