Merge pull request #273 from Acretock/master

Fix unreachable code warning in Win debug

Author: cameron314

concurrentqueue.h

@@ -2906,13 +2906,15 @@ class ConcurrentQueue
 			else if (!new_block_index()) {
 				return false;
 			}
-			localBlockIndex = blockIndex.load(std::memory_order_relaxed);
-			newTail = (localBlockIndex->tail.load(std::memory_order_relaxed) + 1) & (localBlockIndex->capacity - 1);
-			idxEntry = localBlockIndex->index[newTail];
-			assert(idxEntry->key.load(std::memory_order_relaxed) == INVALID_BLOCK_BASE);
-			idxEntry->key.store(blockStartIndex, std::memory_order_relaxed);
-			localBlockIndex->tail.store(newTail, std::memory_order_release);
-			return true;
+			else {
+				localBlockIndex = blockIndex.load(std::memory_order_relaxed);
+				newTail = (localBlockIndex->tail.load(std::memory_order_relaxed) + 1) & (localBlockIndex->capacity - 1);
+				idxEntry = localBlockIndex->index[newTail];
+				assert(idxEntry->key.load(std::memory_order_relaxed) == INVALID_BLOCK_BASE);
+				idxEntry->key.store(blockStartIndex, std::memory_order_relaxed);
+				localBlockIndex->tail.store(newTail, std::memory_order_release);
+				return true;
+			}
 		}
 
 		inline void rewind_block_index_tail()