+namespace detail {
+
+// We call out to an external function to actually print the message as the
+// printing code uses Allocator.h in its implementation.
+void printBumpPtrAllocatorStats(unsigned NumSlabs, size_t BytesAllocated,
+ size_t TotalMemory);
+} // End namespace detail.
+
+/// \brief Allocate memory in an ever growing pool, as if by bump-pointer.
+///
+/// This isn't strictly a bump-pointer allocator as it uses backing slabs of
+/// memory rather than relying on a boundless contiguous heap. However, it has
+/// bump-pointer semantics in that it is a monotonically growing pool of memory
+/// where every allocation is found by merely allocating the next N bytes in
+/// the slab, or the next N bytes in the next slab.
+///
+/// Note that this also has a threshold for forcing allocations above a certain
+/// size into their own slab.
+///
+/// The BumpPtrAllocatorImpl template defaults to using a MallocAllocator
+/// object, which wraps malloc, to allocate memory, but it can be changed to
+/// use a custom allocator.
+template <typename AllocatorT = MallocAllocator, size_t SlabSize = 4096,
+ size_t SizeThreshold = SlabSize>
+class BumpPtrAllocatorImpl
+ : public AllocatorBase<
+ BumpPtrAllocatorImpl<AllocatorT, SlabSize, SizeThreshold>> {