Add mozilla::Span

1 files changed, 32 insertions, 0 deletions

diff --git a/mfbt/Range.h b/mfbt/Range.h
index 47d91bb0c..753fe07f8 100644
--- a/mfbt/Range.h
+++ b/mfbt/Range.h
@@ -9,6 +9,7 @@
 
 #include "mozilla/RangedPtr.h"
 #include "mozilla/TypeTraits.h"
+#include "mozilla/Span.h"
 
 #include <stddef.h>
 
@@ -44,6 +45,19 @@ public:
       mEnd(aOther.mEnd)
   {}
 
+  MOZ_IMPLICIT Range(Span<T> aSpan)
+    : Range(aSpan.Elements(), aSpan.Length())
+  {
+  }
+
+  template<typename U,
+           class = typename EnableIf<IsConvertible<U (*)[], T (*)[]>::value,
+                                     int>::Type>
+  MOZ_IMPLICIT Range(const Span<U>& aSpan)
+    : Range(aSpan.Elements(), aSpan.Length())
+  {
+  }
+
   RangedPtr<T> begin() const { return mStart; }
   RangedPtr<T> end() const { return mEnd; }
   size_t length() const { return mEnd - mStart; }
@@ -51,8 +65,26 @@ public:
   T& operator[](size_t aOffset) const { return mStart[aOffset]; }
 
   explicit operator bool() const { return mStart != nullptr; }
+
+  operator Span<T>() { return Span<T>(mStart.get(), length()); }
+
+  operator Span<const T>() const { return Span<T>(mStart.get(), length()); }
 };
 
+template<class T>
+Span<T>
+MakeSpan(Range<T>& aRange)
+{
+  return aRange;
+}
+
+template<class T>
+Span<const T>
+MakeSpan(const Range<T>& aRange)
+{
+  return aRange;
+}
+
 } // namespace mozilla
 
 #endif /* mozilla_Range_h */