diff --git a/absl/container/inlined_vector.h b/absl/container/inlined_vector.h
index c59fb9386..1ab4b2f44 100644
--- a/absl/container/inlined_vector.h
+++ b/absl/container/inlined_vector.h
@@ -70,7 +70,7 @@ class InlinedVector {
       N > 0, "InlinedVector cannot be instantiated with `0` inlined elements.");
 
   using Storage = inlined_vector_internal::Storage<InlinedVector>;
-  using Allocation = typename Storage::Allocation;
+  using AllocatorTraits = typename Storage::AllocatorTraits;
 
   template <typename Iterator>
   using IsAtLeastForwardIterator = std::is_convertible<
@@ -198,7 +198,8 @@ class InlinedVector {
     if (other.storage_.GetIsAllocated()) {
       // We can just steal the underlying buffer from the source.
       // That leaves the source empty, so we clear its size.
-      storage_.InitAllocation(other.storage_.GetAllocation());
+      storage_.SetAllocatedData(other.storage_.GetAllocatedData());
+      storage_.SetAllocatedCapacity(other.storage_.GetAllocatedCapacity());
       storage_.SetAllocatedSize(other.size());
       other.storage_.SetInlinedSize(0);
     } else {
@@ -231,7 +232,8 @@ class InlinedVector {
       if (alloc == other.storage_.GetAllocator()) {
         // We can just steal the allocation from the source.
         storage_.SetAllocatedSize(other.size());
-        storage_.InitAllocation(other.storage_.GetAllocation());
+        storage_.SetAllocatedData(other.storage_.GetAllocatedData());
+        storage_.SetAllocatedCapacity(other.storage_.GetAllocatedCapacity());
         other.storage_.SetInlinedSize(0);
       } else {
         // We need to use our own allocator
@@ -484,7 +486,8 @@ class InlinedVector {
     if (other.storage_.GetIsAllocated()) {
       clear();
       storage_.SetAllocatedSize(other.size());
-      storage_.InitAllocation(other.storage_.GetAllocation());
+      storage_.SetAllocatedData(other.storage_.GetAllocatedData());
+      storage_.SetAllocatedCapacity(other.storage_.GetAllocatedCapacity());
       other.storage_.SetInlinedSize(0);
     } else {
       if (storage_.GetIsAllocated()) clear();
@@ -789,7 +792,9 @@ class InlinedVector {
     size_type s = size();
     if (storage_.GetIsAllocated()) {
       Destroy(storage_.GetAllocatedData(), storage_.GetAllocatedData() + s);
-      storage_.GetAllocation().Dealloc(storage_.GetAllocator());
+      AllocatorTraits::deallocate(storage_.GetAllocator(),
+                                  storage_.GetAllocatedData(),
+                                  storage_.GetAllocatedCapacity());
     } else if (s != 0) {  // do nothing for empty vectors
       Destroy(storage_.GetInlinedData(), storage_.GetInlinedData() + s);
     }
@@ -841,11 +846,11 @@ class InlinedVector {
     // Reallocate storage and move elements.
     // We can't simply use the same approach as above, because `assign()` would
     // call into `reserve()` internally and reserve larger capacity than we need
-    Allocation new_allocation(storage_.GetAllocator(), s);
+    pointer new_data = AllocatorTraits::allocate(storage_.GetAllocator(), s);
     UninitializedCopy(std::make_move_iterator(storage_.GetAllocatedData()),
                       std::make_move_iterator(storage_.GetAllocatedData() + s),
-                      new_allocation.buffer());
-    ResetAllocation(new_allocation, s);
+                      new_data);
+    ResetAllocation(new_data, s, s);
   }
 
   // `InlinedVector::swap()`
@@ -861,17 +866,21 @@ class InlinedVector {
   template <typename H, typename TheT, size_t TheN, typename TheA>
   friend H AbslHashValue(H h, const absl::InlinedVector<TheT, TheN, TheA>& a);
 
-  void ResetAllocation(Allocation new_allocation, size_type new_size) {
+  void ResetAllocation(pointer new_data, size_type new_capacity,
+                       size_type new_size) {
     if (storage_.GetIsAllocated()) {
       Destroy(storage_.GetAllocatedData(),
               storage_.GetAllocatedData() + size());
       assert(begin() == storage_.GetAllocatedData());
-      storage_.GetAllocation().Dealloc(storage_.GetAllocator());
-      storage_.GetAllocation() = new_allocation;
+      AllocatorTraits::deallocate(storage_.GetAllocator(),
+                                  storage_.GetAllocatedData(),
+                                  storage_.GetAllocatedCapacity());
     } else {
       Destroy(storage_.GetInlinedData(), storage_.GetInlinedData() + size());
-      storage_.InitAllocation(new_allocation);  // bug: only init once
     }
+
+    storage_.SetAllocatedData(new_data);
+    storage_.SetAllocatedCapacity(new_capacity);
     storage_.SetAllocatedSize(new_size);
   }
 
@@ -925,13 +934,13 @@ class InlinedVector {
       new_capacity <<= 1;
     }
 
-    Allocation new_allocation(storage_.GetAllocator(), new_capacity);
+    pointer new_data =
+        AllocatorTraits::allocate(storage_.GetAllocator(), new_capacity);
 
     UninitializedCopy(std::make_move_iterator(data()),
-                      std::make_move_iterator(data() + s),
-                      new_allocation.buffer());
+                      std::make_move_iterator(data() + s), new_data);
 
-    ResetAllocation(new_allocation, s);
+    ResetAllocation(new_data, new_capacity, s);
   }
 
   // Shift all elements from `position` to `end()` by `n` places to the right.
@@ -957,15 +966,15 @@ class InlinedVector {
       }
       // Move everyone into the new allocation, leaving a gap of `n` for the
       // requested shift.
-      Allocation new_allocation(storage_.GetAllocator(), new_capacity);
+      pointer new_data =
+          AllocatorTraits::allocate(storage_.GetAllocator(), new_capacity);
       size_type index = position - begin();
       UninitializedCopy(std::make_move_iterator(data()),
-                        std::make_move_iterator(data() + index),
-                        new_allocation.buffer());
+                        std::make_move_iterator(data() + index), new_data);
       UninitializedCopy(std::make_move_iterator(data() + index),
                         std::make_move_iterator(data() + s),
-                        new_allocation.buffer() + index + n);
-      ResetAllocation(new_allocation, s);
+                        new_data + index + n);
+      ResetAllocation(new_data, new_capacity, s);
 
       // New allocation means our iterator is invalid, so we'll recalculate.
       // Since the entire gap is in new space, there's no used space to reuse.
@@ -1005,23 +1014,25 @@ class InlinedVector {
     assert(size() == capacity());
     const size_type s = size();
 
-    Allocation new_allocation(storage_.GetAllocator(), 2 * capacity());
+    size_type new_capacity = 2 * capacity();
+    pointer new_data =
+        AllocatorTraits::allocate(storage_.GetAllocator(), new_capacity);
 
     reference new_element =
-        Construct(new_allocation.buffer() + s, std::forward<Args>(args)...);
+        Construct(new_data + s, std::forward<Args>(args)...);
     UninitializedCopy(std::make_move_iterator(data()),
-                      std::make_move_iterator(data() + s),
-                      new_allocation.buffer());
+                      std::make_move_iterator(data() + s), new_data);
 
-    ResetAllocation(new_allocation, s + 1);
+    ResetAllocation(new_data, new_capacity, s + 1);
 
     return new_element;
   }
 
   void InitAssign(size_type n) {
     if (n > static_cast<size_type>(N)) {
-      Allocation new_allocation(storage_.GetAllocator(), n);
-      storage_.InitAllocation(new_allocation);
+      pointer new_data = AllocatorTraits::allocate(storage_.GetAllocator(), n);
+      storage_.SetAllocatedData(new_data);
+      storage_.SetAllocatedCapacity(n);
       UninitializedFill(storage_.GetAllocatedData(),
                         storage_.GetAllocatedData() + n);
       storage_.SetAllocatedSize(n);
@@ -1034,8 +1045,9 @@ class InlinedVector {
 
   void InitAssign(size_type n, const_reference v) {
     if (n > static_cast<size_type>(N)) {
-      Allocation new_allocation(storage_.GetAllocator(), n);
-      storage_.InitAllocation(new_allocation);
+      pointer new_data = AllocatorTraits::allocate(storage_.GetAllocator(), n);
+      storage_.SetAllocatedData(new_data);
+      storage_.SetAllocatedCapacity(n);
       UninitializedFill(storage_.GetAllocatedData(),
                         storage_.GetAllocatedData() + n, v);
       storage_.SetAllocatedSize(n);
@@ -1117,15 +1129,15 @@ class InlinedVector {
   }
 
   void SwapImpl(InlinedVector& other) {
-    using std::swap;  // Augment ADL with `std::swap`.
+    using std::swap;
 
     bool is_allocated = storage_.GetIsAllocated();
     bool other_is_allocated = other.storage_.GetIsAllocated();
 
     if (is_allocated && other_is_allocated) {
       // Both out of line, so just swap the tag, allocation, and allocator.
-      storage_.SwapSizeAndIsAllocated(other.storage_);
-      swap(storage_.GetAllocation(), other.storage_.GetAllocation());
+      storage_.SwapSizeAndIsAllocated(std::addressof(other.storage_));
+      storage_.SwapAllocatedSizeAndCapacity(std::addressof(other.storage_));
       swap(storage_.GetAllocator(), other.storage_.GetAllocator());
 
       return;
@@ -1155,7 +1167,7 @@ class InlinedVector {
       a->Destroy(a->storage_.GetInlinedData() + b_size,
                  a->storage_.GetInlinedData() + a_size);
 
-      storage_.SwapSizeAndIsAllocated(other.storage_);
+      storage_.SwapSizeAndIsAllocated(std::addressof(other.storage_));
       swap(storage_.GetAllocator(), other.storage_.GetAllocator());
 
       assert(b->size() == a_size);
@@ -1183,11 +1195,11 @@ class InlinedVector {
     static_cast<void>(b_size);
 
     // Made Local copies of `size()`, these can now be swapped
-    a->storage_.SwapSizeAndIsAllocated(b->storage_);
+    a->storage_.SwapSizeAndIsAllocated(std::addressof(b->storage_));
 
-    // Copy `b_allocation` out before `b`'s union gets clobbered by
-    // `inline_space`
-    Allocation b_allocation = b->storage_.GetAllocation();
+    // Copy out before `b`'s union gets clobbered by `inline_space`
+    pointer b_data = b->storage_.GetAllocatedData();
+    size_type b_capacity = b->storage_.GetAllocatedCapacity();
 
     b->UninitializedCopy(a->storage_.GetInlinedData(),
                          a->storage_.GetInlinedData() + a_size,
@@ -1195,7 +1207,8 @@ class InlinedVector {
     a->Destroy(a->storage_.GetInlinedData(),
                a->storage_.GetInlinedData() + a_size);
 
-    a->storage_.GetAllocation() = b_allocation;
+    a->storage_.SetAllocatedData(b_data);
+    a->storage_.SetAllocatedCapacity(b_capacity);
 
     if (a->storage_.GetAllocator() != b->storage_.GetAllocator()) {
       swap(a->storage_.GetAllocator(), b->storage_.GetAllocator());
diff --git a/absl/container/internal/inlined_vector.h b/absl/container/internal/inlined_vector.h
index 7aa05b6a9..168d5b4e1 100644
--- a/absl/container/internal/inlined_vector.h
+++ b/absl/container/internal/inlined_vector.h
@@ -33,8 +33,6 @@ template <template <typename, size_t, typename> class InlinedVector, typename T,
           size_t N, typename A>
 class Storage<InlinedVector<T, N, A>> {
  public:
-  class Allocation;  // TODO(johnsoncj): Remove after migration
-
   using allocator_type = A;
   using value_type = typename allocator_type::value_type;
   using pointer = typename allocator_type::pointer;
@@ -48,6 +46,7 @@ class Storage<InlinedVector<T, N, A>> {
   using const_iterator = const_pointer;
   using reverse_iterator = std::reverse_iterator<iterator>;
   using const_reverse_iterator = std::reverse_iterator<const_iterator>;
+  using AllocatorTraits = std::allocator_traits<allocator_type>;
 
   explicit Storage(const allocator_type& alloc)
       : metadata_(alloc, /* empty and inlined */ 0) {}
@@ -56,30 +55,25 @@ class Storage<InlinedVector<T, N, A>> {
 
   bool GetIsAllocated() const { return GetSizeAndIsAllocated() & 1; }
 
-  Allocation& GetAllocation() {
-    return reinterpret_cast<Allocation&>(rep_.allocation_storage.allocation);
-  }
-
-  const Allocation& GetAllocation() const {
-    return reinterpret_cast<const Allocation&>(
-        rep_.allocation_storage.allocation);
-  }
-
   pointer GetInlinedData() {
     return reinterpret_cast<pointer>(
-        std::addressof(rep_.inlined_storage.inlined[0]));
+        std::addressof(data_.inlined.inlined_data[0]));
   }
 
   const_pointer GetInlinedData() const {
     return reinterpret_cast<const_pointer>(
-        std::addressof(rep_.inlined_storage.inlined[0]));
+        std::addressof(data_.inlined.inlined_data[0]));
   }
 
-  pointer GetAllocatedData() { return GetAllocation().buffer(); }
+  pointer GetAllocatedData() { return data_.allocated.allocated_data; }
 
-  const_pointer GetAllocatedData() const { return GetAllocation().buffer(); }
+  const_pointer GetAllocatedData() const {
+    return data_.allocated.allocated_data;
+  }
 
-  size_type GetAllocatedCapacity() const { return GetAllocation().capacity(); }
+  size_type GetAllocatedCapacity() const {
+    return data_.allocated.allocated_capacity;
+  }
 
   allocator_type& GetAllocator() { return metadata_.template get<0>(); }
 
@@ -95,34 +89,23 @@ class Storage<InlinedVector<T, N, A>> {
 
   void AddSize(size_type count) { GetSizeAndIsAllocated() += count << 1; }
 
-  void InitAllocation(const Allocation& allocation) {
-    new (static_cast<void*>(std::addressof(rep_.allocation_storage.allocation)))
-        Allocation(allocation);
+  void SetAllocatedData(pointer data) {
+    data_.allocated.allocated_data = data;
   }
 
-  void SwapSizeAndIsAllocated(Storage& other) {
+  void SetAllocatedCapacity(size_type capacity) {
+    data_.allocated.allocated_capacity = capacity;
+  }
+
+  void SwapSizeAndIsAllocated(Storage* other) {
     using std::swap;
-    swap(GetSizeAndIsAllocated(), other.GetSizeAndIsAllocated());
+    swap(GetSizeAndIsAllocated(), other->GetSizeAndIsAllocated());
   }
 
-  // TODO(johnsoncj): Make the below types private after migration
-  class Allocation {
-    size_type capacity_;
-    pointer buffer_;
-
-   public:
-    Allocation(allocator_type& a, size_type capacity)
-        : capacity_(capacity), buffer_(Create(a, capacity)) {}
-    void Dealloc(allocator_type& a) {
-      std::allocator_traits<allocator_type>::deallocate(a, buffer_, capacity_);
-    }
-    size_type capacity() const { return capacity_; }
-    const_pointer buffer() const { return buffer_; }
-    pointer buffer() { return buffer_; }
-    static pointer Create(allocator_type& a, size_type n) {
-      return std::allocator_traits<allocator_type>::allocate(a, n);
-    }
-  };
+  void SwapAllocatedSizeAndCapacity(Storage* other) {
+    using std::swap;
+    swap(data_.allocated, other->data_.allocated);
+  }
 
  private:
   size_type& GetSizeAndIsAllocated() { return metadata_.template get<1>(); }
@@ -131,29 +114,27 @@ class Storage<InlinedVector<T, N, A>> {
     return metadata_.template get<1>();
   }
 
-  // Stores either the inlined or allocated representation
-  union Rep {
-    using ValueTypeBuffer =
-        absl::aligned_storage_t<sizeof(value_type), alignof(value_type)>;
-    using AllocationBuffer =
-        absl::aligned_storage_t<sizeof(Allocation), alignof(Allocation)>;
+  using Metadata =
+      container_internal::CompressedTuple<allocator_type, size_type>;
 
-    // Structs wrap the buffers to perform indirection that solves a bizarre
-    // compilation error on Visual Studio (all known versions).
-    struct InlinedRep {
-      ValueTypeBuffer inlined[N];
-    };
-
-    struct AllocatedRep {
-      AllocationBuffer allocation;
-    };
-
-    InlinedRep inlined_storage;
-    AllocatedRep allocation_storage;
+  struct Allocated {
+    pointer allocated_data;
+    size_type allocated_capacity;
   };
 
-  container_internal::CompressedTuple<allocator_type, size_type> metadata_;
-  Rep rep_;
+  struct Inlined {
+    using InlinedDataElement =
+        absl::aligned_storage_t<sizeof(value_type), alignof(value_type)>;
+    InlinedDataElement inlined_data[N];
+  };
+
+  union Data {
+    Allocated allocated;
+    Inlined inlined;
+  };
+
+  Metadata metadata_;
+  Data data_;
 };
 
 }  // namespace inlined_vector_internal
diff --git a/absl/copts/GENERATED_AbseilCopts.cmake b/absl/copts/GENERATED_AbseilCopts.cmake
index cf38ec124..5543638c8 100644
--- a/absl/copts/GENERATED_AbseilCopts.cmake
+++ b/absl/copts/GENERATED_AbseilCopts.cmake
@@ -204,7 +204,7 @@ list(APPEND ABSL_MSVC_FLAGS
 )
 
 list(APPEND ABSL_MSVC_LINKOPTS
-    "/ignore:4221"
+    "-ignore:4221"
 )
 
 list(APPEND ABSL_MSVC_TEST_FLAGS
diff --git a/absl/copts/GENERATED_copts.bzl b/absl/copts/GENERATED_copts.bzl
index 52e1a949f..10caa78a8 100644
--- a/absl/copts/GENERATED_copts.bzl
+++ b/absl/copts/GENERATED_copts.bzl
@@ -205,7 +205,7 @@ ABSL_MSVC_FLAGS = [
 ]
 
 ABSL_MSVC_LINKOPTS = [
-    "/ignore:4221",
+    "-ignore:4221",
 ]
 
 ABSL_MSVC_TEST_FLAGS = [
diff --git a/absl/copts/copts.py b/absl/copts/copts.py
index 880ff991b..cdcf61d67 100644
--- a/absl/copts/copts.py
+++ b/absl/copts/copts.py
@@ -189,6 +189,6 @@ COPT_VARS = {
         MSVC_STYLE_EXCEPTIONS_FLAGS,
     "ABSL_MSVC_LINKOPTS": [
         # Object file doesn't export any previously undefined symbols
-        "/ignore:4221",
+        "-ignore:4221",
     ],
 }