diff --git a/kernel/drivertools.cc b/kernel/drivertools.cc
index 27ebd20b284..805532e9b29 100644
--- a/kernel/drivertools.cc
+++ b/kernel/drivertools.cc
@@ -910,6 +910,38 @@ bool DriveChunkMultiple::try_append(DriveChunkMultiple const &chunk)
   return true;
 }
 
+DriveChunkMultiple::DriveChunkMultiple(DriveBitMultiple const &bit)
+    : width_(1)
+{
+    for (auto const &bit : bit.multiple())
+        multiple_.emplace(bit);
+}
+
+pool<DriveChunk> const &DriveChunkMultiple::multiple() const
+{
+    return multiple_;
+}
+
+int DriveChunkMultiple::size() const { return width_; }
+
+
+bool DriveChunkMultiple::operator==(const DriveChunkMultiple &other) const
+{
+    return width_ == other.width_ && multiple_ == other.multiple_;
+}
+
+bool DriveChunkMultiple::operator<(const DriveChunkMultiple &other) const
+{
+    if (multiple_.size() < other.multiple_.size())
+        multiple_.sort();
+    return false; // TODO: implement, canonicalize order
+}
+
+unsigned int DriveChunkMultiple::hash() const
+{
+    return mkhash(width_, multiple_.hash());
+}
+
 bool DriveChunk::can_append(DriveBit const &bit) const
 {
   if (size() == 0)
diff --git a/kernel/drivertools.h b/kernel/drivertools.h
index 4f6c7a7befe..51b72c49162 100644
--- a/kernel/drivertools.h
+++ b/kernel/drivertools.h
@@ -265,47 +265,23 @@ struct DriveChunkMarker
 struct DriveChunkMultiple
 {
 private:
-  mutable pool<DriveChunk> multiple_;
-  int width_;
+    mutable pool<DriveChunk> multiple_;
+    int width_;
 
 public:
-  pool<DriveChunk> const &multiple() const { return multiple_; }
+    pool<DriveChunk> const &multiple() const;
 
-  DriveChunkMultiple(DriveBitMultiple const &bit) : width_(1) {
-    for (auto const &bit : bit.multiple())
-      multiple_.emplace(bit);
-  }
-
-  int size() const { return width_; }
-
-  DriveBitMultiple operator[](int i) const;
-
-  bool can_append(DriveBitMultiple const &bit) const;
-
-  bool try_append(DriveBitMultiple const &bit);
+    DriveChunkMultiple(DriveBitMultiple const &bit);
 
-
-  bool can_append(DriveChunkMultiple const &bit) const;
-
-  bool try_append(DriveChunkMultiple const &bit);
-
-  bool operator==(const DriveChunkMultiple &other) const
-  {
-    return width_ == other.width_ && multiple_ == other.multiple_;
-  }
-
-  bool operator<(const DriveChunkMultiple &other) const
-  {
-    if (multiple_.size() < other.multiple_.size())
-
-      multiple_.sort();
-    return false; // TODO implement, canonicalize order
-  }
-
-  unsigned int hash() const
-  {
-    return mkhash(width_, multiple_.hash());
-  }
+    int size() const;
+    DriveBitMultiple operator[](int i) const;
+    bool can_append(DriveBitMultiple const &bit) const;
+    bool try_append(DriveBitMultiple const &bit);
+    bool can_append(DriveChunkMultiple const &bit) const;
+    bool try_append(DriveChunkMultiple const &bit);
+    bool operator==(const DriveChunkMultiple &other) const;
+    bool operator<(const DriveChunkMultiple &other) const;
+    unsigned int hash() const;
 };
 
 struct DriveChunk