Add mozilla::Span

2 files changed, 167 insertions, 0 deletions

diff --git a/xpcom/glue/nsTArray.h b/xpcom/glue/nsTArray.h
index ca74a41f76..c86772a8e9 100644
--- a/xpcom/glue/nsTArray.h
+++ b/xpcom/glue/nsTArray.h
@@ -19,6 +19,7 @@
 #include "mozilla/Move.h"
 #include "mozilla/ReverseIterator.h"
 #include "mozilla/TypeTraits.h"
+#include "mozilla/Span.h"
 
 #include <string.h>
 
@@ -1112,6 +1113,18 @@ public:
   const_reverse_iterator rend() const { return const_reverse_iterator(begin()); }
   const_reverse_iterator crend() const { return rend(); }
 
+  // Span integration
+
+  operator mozilla::Span<elem_type>()
+  {
+    return mozilla::Span<elem_type>(Elements(), Length());
+  }
+
+  operator mozilla::Span<const elem_type>() const
+  {
+    return mozilla::Span<const elem_type>(Elements(), Length());
+ }
+
   //
   // Search methods
   //
@@ -1336,6 +1349,16 @@ protected:
     return ReplaceElementsAt<Item, ActualAlloc>(
       aStart, aCount, aArray.Elements(), aArray.Length());
   }
+
+  template<class Item, typename ActualAlloc = Alloc>
+  elem_type* ReplaceElementsAt(index_type aStart,
+                               size_type aCount,
+                               mozilla::Span<const Item> aSpan)
+  {
+    return ReplaceElementsAt<Item, ActualAlloc>(
+      aStart, aCount, aSpan.Elements(), aSpan.Length());
+  }
+
 public:
 
   template<class Item>
@@ -1347,6 +1370,15 @@ public:
     return ReplaceElementsAt<Item, FallibleAlloc>(aStart, aCount, aArray);
   }
 
+  template<class Item>
+  MOZ_MUST_USE elem_type* ReplaceElementsAt(index_type aStart,
+                                            size_type aCount,
+                                            mozilla::Span<const Item> aSpan,
+                                            const mozilla::fallible_t&)
+  {
+    return ReplaceElementsAt<Item, FallibleAlloc>(aStart, aCount, aSpan);
+  }
+
   // A variation on the ReplaceElementsAt method defined above.
 protected:
   template<class Item, typename ActualAlloc = Alloc>
@@ -1399,6 +1431,15 @@ protected:
     return ReplaceElementsAt<Item, ActualAlloc>(
       aIndex, 0, aArray.Elements(), aArray.Length());
   }
+
+  template<class Item, typename ActualAlloc = Alloc>
+  elem_type* InsertElementsAt(index_type aIndex,
+                              mozilla::Span<const Item> aSpan)
+  {
+    return ReplaceElementsAt<Item, ActualAlloc>(
+      aIndex, 0, aSpan.Elements(), aSpan.Length());
+  }
+
 public:
 
   template<class Item, class Allocator>
@@ -1425,6 +1466,14 @@ public:
     return InsertElementAt<FallibleAlloc>(aIndex);
   }
 
+  template<class Item>
+  MOZ_MUST_USE elem_type* InsertElementsAt(index_type aIndex,
+                                           mozilla::Span<const Item> aSpan,
+                                           const mozilla::fallible_t&)
+  {
+    return InsertElementsAt<Item, FallibleAlloc>(aIndex, aSpan);
+  }
+
   // Insert a new element, move constructing if possible.
 protected:
   template<class Item, typename ActualAlloc = Alloc>
@@ -1526,6 +1575,13 @@ protected:
   template<class Item, typename ActualAlloc = Alloc>
   elem_type* AppendElements(const Item* aArray, size_type aArrayLen);
 
+  template<class Item, typename ActualAlloc = Alloc>
+  elem_type* AppendElements(mozilla::Span<const Item> aSpan)
+  {
+    return AppendElements<Item, FallibleAlloc>(aSpan.Elements(),
+                                               aSpan.Length());
+  }
+
 public:
 
   template<class Item>
@@ -1536,6 +1592,15 @@ public:
     return AppendElements<Item, FallibleAlloc>(aArray, aArrayLen);
   }
 
+  template<class Item>
+  /* MOZ_MUST_USE */
+  elem_type* AppendElements(mozilla::Span<const Item> aSpan,
+                            const mozilla::fallible_t&)
+  {
+    return AppendElements<Item, FallibleAlloc>(aSpan.Elements(),
+                                               aSpan.Length());
+  }
+
   // A variation on the AppendElements method defined above.
 protected:
   template<class Item, class Allocator, typename ActualAlloc = Alloc>
@@ -2347,6 +2412,25 @@ struct nsTArray_CopyChooser<AutoTArray<E, N>>
   typedef nsTArray_CopyWithConstructors<AutoTArray<E, N>> Type;
 };
 
+// Span integration
+namespace mozilla {
+
+template<class ElementType, class TArrayAlloc>
+Span<ElementType>
+MakeSpan(nsTArray_Impl<ElementType, TArrayAlloc>& aTArray)
+{
+  return aTArray;
+}
+
+template<class ElementType, class TArrayAlloc>
+Span<const ElementType>
+MakeSpan(const nsTArray_Impl<ElementType, TArrayAlloc>& aTArray)
+{
+  return aTArray;
+}
+
+} // namespace mozilla
+
 // Assert that AutoTArray doesn't have any extra padding inside.
 //
 // It's important that the data stored in this auto array takes up a multiple of
diff --git a/xpcom/string/nsTSubstring.h b/xpcom/string/nsTSubstring.h
index a08036b1f0..53b4fb9a82 100644
--- a/xpcom/string/nsTSubstring.h
+++ b/xpcom/string/nsTSubstring.h
@@ -7,6 +7,8 @@
 
 #include "mozilla/Casting.h"
 #include "mozilla/MemoryReporting.h"
+#include "mozilla/IntegerTypeTraits.h"
+#include "mozilla/Span.h"
 
 #ifndef MOZILLA_INTERNAL_API
 #error Cannot use internal string classes without MOZILLA_INTERNAL_API defined. Use the frozen header nsStringAPI.h instead.
@@ -798,6 +800,68 @@ public:
   }
 #endif
 
+  /**
+   * Span integration
+   */
+
+  operator mozilla::Span<char_type>()
+  {
+    return mozilla::MakeSpan(BeginWriting(), Length());
+  }
+
+  operator mozilla::Span<const char_type>() const
+  {
+    return mozilla::MakeSpan(BeginReading(), Length());
+  }
+
+  void Append(mozilla::Span<const char_type> aSpan)
+  {
+    auto len = aSpan.Length();
+    MOZ_RELEASE_ASSERT(len <= mozilla::MaxValue<size_type>::value);
+    Append(aSpan.Elements(), len);
+  }
+
+  MOZ_MUST_USE bool Append(mozilla::Span<const char_type> aSpan,
+                           const fallible_t& aFallible)
+  {
+    auto len = aSpan.Length();
+    if (len > mozilla::MaxValue<size_type>::value) {
+      return false;
+    }
+    return Append(aSpan.Elements(), len, aFallible);
+  }
+
+#if !defined(CharT_is_PRUnichar)
+  operator mozilla::Span<uint8_t>()
+  {
+    return mozilla::MakeSpan(reinterpret_cast<uint8_t*>(BeginWriting()),
+                             Length());
+  }
+
+  operator mozilla::Span<const uint8_t>() const
+  {
+    return mozilla::MakeSpan(reinterpret_cast<const uint8_t*>(BeginReading()),
+                             Length());
+  }
+
+  void Append(mozilla::Span<const uint8_t> aSpan)
+  {
+    auto len = aSpan.Length();
+    MOZ_RELEASE_ASSERT(len <= mozilla::MaxValue<size_type>::value);
+    Append(reinterpret_cast<const char*>(aSpan.Elements()), len);
+  }
+
+  MOZ_MUST_USE bool Append(mozilla::Span<const uint8_t> aSpan,
+                           const fallible_t& aFallible)
+  {
+    auto len = aSpan.Length();
+    if (len > mozilla::MaxValue<size_type>::value) {
+      return false;
+    }
+    return Append(
+      reinterpret_cast<const char*>(aSpan.Elements()), len, aFallible);
+  }
+#endif
 
   /**
    * string data is never null, but can be marked void.  if true, the
@@ -1184,3 +1248,22 @@ operator>(const nsTSubstring_CharT::base_string_type& aLhs,
 {
   return Compare(aLhs, aRhs) > 0;
 }
+
+/**
+ * Span integration
+ */
+namespace mozilla {
+
+inline Span<CharT>
+MakeSpan(nsTSubstring_CharT& aString)
+{
+  return aString;
+}
+
+inline Span<const CharT>
+MakeSpan(const nsTSubstring_CharT& aString)
+{
+  return aString;
+}
+
+} // namespace mozilla