Bug 1768632: Make EnumSet compile for MSVC. r=glandium

Differential Revision: https://phabricator.services.mozilla.com/D154338

mfbt/BitSet.h

@@ -75,7 +75,7 @@ class BitSet {
     PodCopy(mStorage.begin(), aStorage.Elements(), kNumWords);
   }
 
-  constexpr size_t Size() const { return N; }
+  static constexpr size_t Size() { return N; }
 
   constexpr bool Test(size_t aPos) const {
     MOZ_ASSERT(aPos < N);

mfbt/EnumSet.h

@@ -318,15 +318,15 @@ class EnumSet {
 #endif
   }
 
-  constexpr size_t MaxBits() const {
+  static constexpr size_t MaxBits() {
     if constexpr (std::is_unsigned_v<Serialized>) {
       return sizeof(Serialized) * 8;
     } else {
-      return mBitField.Size();
+      return Serialized::Size();
     }
-  };
+  }
 
-  static constexpr size_t kMaxBits = EnumSet().MaxBits();
+  static constexpr size_t kMaxBits = MaxBits();
 
   Serialized mBitField;
 

mfbt/tests/TestBitSet.cpp

@@ -83,12 +83,12 @@ class BitSetSuite {
     MOZ_RELEASE_ASSERT(bitset[kBitsPerWord + 1]);
 
     bitset.ResetAll();
-    for (size_t i = 0; i < bitset.Size(); i++) {
+    for (size_t i = 0; i < decltype(bitset)::Size(); i++) {
       MOZ_RELEASE_ASSERT(!bitset[i]);
     }
 
     bitset.SetAll();
-    for (size_t i = 0; i < bitset.Size(); i++) {
+    for (size_t i = 0; i < decltype(bitset)::Size(); i++) {
       MOZ_RELEASE_ASSERT(bitset[i]);
     }
 
@@ -96,7 +96,7 @@ class BitSetSuite {
     MOZ_RELEASE_ASSERT(bitset.Storage()[1] == 3);
 
     bitset.ResetAll();
-    for (size_t i = 0; i < bitset.Size(); i++) {
+    for (size_t i = 0; i < decltype(bitset)::Size(); i++) {
       MOZ_RELEASE_ASSERT(!bitset[i]);
     }
   }