fix compilation issues on MSVC

Summary:
MSVC seems to have a bug when handling private classes that
are both part of the inheritence hierarchy (private superclass of a
superclass) and available as a template parameter, incorrectly claiming
that the class is inaccessible due to private inheritance. This diff
works around the issue. It also adds an explicit case to avoid a narrowing
warning generated by MSVC.

(Note: this ignores all push blocking failures!)

Reviewed By: yfeldblum, mjoras

Differential Revision: D19561643

fbshipit-source-id: 494d1611ce662a0eb6c441c64479d3c5d2bbd5b6

folly/container/detail/F14Policy.h

@@ -1027,16 +1027,16 @@ class VectorContainerPolicy : public BasePolicy<
       KeyEqualOrVoid,
       AllocOrVoid,
       uint32_t>;
-  using Alloc = typename Super::Alloc;
+  using Value = typename Super::Value;
+  using Alloc = Defaulted<AllocOrVoid, DefaultAlloc<Value>>;
   using AllocTraits = typename Super::AllocTraits;
   using ByteAlloc = typename Super::ByteAlloc;
   using ByteAllocTraits = typename Super::ByteAllocTraits;
   using BytePtr = typename Super::BytePtr;
-  using Hasher = typename Super::Hasher;
+  using Hasher = Defaulted<HasherOrVoid, DefaultHasher<Key>>;
   using Item = typename Super::Item;
   using ItemIter = typename Super::ItemIter;
-  using KeyEqual = typename Super::KeyEqual;
-  using Value = typename Super::Value;
+  using KeyEqual = Defaulted<KeyEqualOrVoid, DefaultKeyEqual<Key>>;
 
   using Super::kAllocIsAlwaysEqual;
 

folly/container/detail/F14Table.h

@@ -1724,8 +1724,8 @@ class F14Table : public Policy {
 
     // Use the source's capacity, unless it is oversized.
     auto upperLimit = computeChunkCountAndScale(src.size(), false, false);
-    auto ccas =
-        std::make_pair(src.chunkMask_ + 1, src.chunks_->capacityScale());
+    auto ccas = std::make_pair(
+        std::size_t{src.chunkMask_} + 1, src.chunks_->capacityScale());
     FOLLY_SAFE_DCHECK(
         ccas.first >= upperLimit.first,
         "rounded chunk count can't be bigger than actual");