Bug 1891497 - Add mozilla::Span constructor for EnumeratedArray. r=glandium

Just like the mozilla::Array/std::array ones.

Differential Revision: https://phabricator.services.mozilla.com/D207389

mfbt/Span.h

@@ -41,6 +41,9 @@ namespace mozilla {
 template <typename T, size_t Length>
 class Array;
 
+template <typename Enum, typename T, size_t Length>
+class EnumeratedArray;
+
 // Stuff from gsl_util
 
 // narrow_cast(): a searchable way to do narrowing casts of values
@@ -487,6 +490,23 @@ class Span {
       const mozilla::Array<std::remove_const_t<element_type>, N>& aArr)
       : storage_(&aArr[0], span_details::extent_type<N>()) {}
 
+  /**
+   * Constructor for mozilla::EnumeratedArray.
+   */
+  template <size_t N, class Enum,
+            class ArrayElementType = std::remove_const_t<element_type>>
+  constexpr MOZ_IMPLICIT Span(
+      mozilla::EnumeratedArray<Enum, ArrayElementType, N>& aArr)
+      : storage_(&aArr[Enum(0)], span_details::extent_type<N>()) {}
+
+  /**
+   * Constructor for const mozilla::EnumeratedArray.
+   */
+  template <size_t N, class Enum>
+  constexpr MOZ_IMPLICIT Span(const mozilla::EnumeratedArray<
+                              Enum, std::remove_const_t<element_type>, N>& aArr)
+      : storage_(&aArr[Enum(0)], span_details::extent_type<N>()) {}
+
   /**
    * Constructor for mozilla::UniquePtr holding an array and length.
    */
@@ -852,6 +872,12 @@ Span(mozilla::Array<T, Extent>&) -> Span<T, Extent>;
 template <typename T, size_t Extent>
 Span(const mozilla::Array<T, Extent>&) -> Span<const T, Extent>;
 
+template <typename Enum, typename T, size_t Extent>
+Span(mozilla::EnumeratedArray<Enum, T, Extent>&) -> Span<T, Extent>;
+
+template <typename Enum, typename T, size_t Extent>
+Span(const mozilla::EnumeratedArray<Enum, T, Extent>&) -> Span<const T, Extent>;
+
 // [Span.comparison], Span comparison operators
 template <class ElementType, size_t FirstExtent, size_t SecondExtent>
 inline constexpr bool operator==(const Span<ElementType, FirstExtent>& l,

widget/cocoa/nsChildView.mm

@@ -1760,7 +1760,7 @@ static void MakeRegionsNonOverlapping(Span<LayoutDeviceIntRegion> aRegions) {
 void nsChildView::UpdateVibrancy(
     const nsTArray<ThemeGeometry>& aThemeGeometries) {
   auto regions = GatherVibrantRegions(aThemeGeometries);
-  MakeRegionsNonOverlapping(Span(regions.begin(), regions.end()));
+  MakeRegionsNonOverlapping(regions);
 
   auto& vm = EnsureVibrancyManager();
   bool changed = false;