Random improvements for ArrayRefView.

Author: rjmccall

include/swift/Basic/ArrayRefView.h

@@ -29,6 +29,7 @@ template <class Orig, class Projected, Projected (&Project)(const Orig &),
 class ArrayRefView {
   llvm::ArrayRef<Orig> Array;
 public:
+  ArrayRefView() {}
   ArrayRefView(llvm::ArrayRef<Orig> array) : Array(array) {}
 
   class iterator {
@@ -111,6 +112,41 @@ class ArrayRefView {
                   "original array access not enabled for this view");
     return Array;
   }
+
+  friend bool operator==(ArrayRefView lhs, ArrayRefView rhs) {
+    if (lhs.size() != rhs.size())
+      return false;
+    for (auto i : indices(lhs))
+      if (lhs[i] != rhs[i])
+        return false;
+    return true;
+  }
+  friend bool operator==(llvm::ArrayRef<Projected> lhs, ArrayRefView rhs) {
+    if (lhs.size() != rhs.size())
+      return false;
+    for (auto i : indices(lhs))
+      if (lhs[i] != rhs[i])
+        return false;
+    return true;
+  }
+  friend bool operator==(ArrayRefView lhs, llvm::ArrayRef<Projected> rhs) {
+    if (lhs.size() != rhs.size())
+      return false;
+    for (auto i : indices(lhs))
+      if (lhs[i] != rhs[i])
+        return false;
+    return true;
+  }
+
+  friend bool operator!=(ArrayRefView lhs, ArrayRefView rhs) {
+    return !(lhs == rhs);
+  }
+  friend bool operator!=(llvm::ArrayRef<Projected> lhs, ArrayRefView rhs) {
+    return !(lhs == rhs);
+  }
+  friend bool operator!=(ArrayRefView lhs, llvm::ArrayRef<Projected> rhs) {
+    return !(lhs == rhs);
+  }
 };
 
 } // end namespace swift

lib/IDE/TypeReconstruction.cpp

@@ -694,7 +694,7 @@ static void VisitNodeAddressor(
   // and they bear no connection to their original variable at the interface
   // level
   CanFunctionType swift_can_func_type =
-    CanFunctionType::get(AnyFunctionType::CanParamArrayRef({}),
+    CanFunctionType::get(AnyFunctionType::CanParamArrayRef(),
                          ast->TheRawPointerType,
                          AnyFunctionType::ExtInfo());
   result._types.push_back(swift_can_func_type.getPointer());

lib/IRGen/GenMeta.cpp

@@ -1684,7 +1684,7 @@ namespace {
         // All function types look like () -> ().
         // FIXME: It'd be nice not to have to call through the runtime here.
         return IGF.emitTypeMetadataRef(
-                 CanFunctionType::get(AnyFunctionType::CanParamArrayRef({ }),
+                 CanFunctionType::get(AnyFunctionType::CanParamArrayRef(),
                                       C.TheEmptyTupleType,
                                       AnyFunctionType::ExtInfo()));
       case SILFunctionType::Representation::Block:
@@ -1866,7 +1866,7 @@ namespace {
       case SILFunctionType::Representation::Thick:
         // All function types look like () -> ().
         return emitFromValueWitnessTable(
-                 CanFunctionType::get(AnyFunctionType::CanParamArrayRef({}),
+                 CanFunctionType::get(AnyFunctionType::CanParamArrayRef(),
                                       C.TheEmptyTupleType,
                                       AnyFunctionType::ExtInfo()));
       case SILFunctionType::Representation::Block:

lib/IRGen/GenReflection.cpp

@@ -928,7 +928,7 @@ void IRGenModule::emitBuiltinReflectionMetadata() {
     // extra inhabitants as these. But maybe it's best not to codify
     // that in the ABI anyway.
     CanType thinFunction = CanFunctionType::get(
-      AnyFunctionType::CanParamArrayRef({}), Context.TheEmptyTupleType,
+      AnyFunctionType::CanParamArrayRef(), Context.TheEmptyTupleType,
       AnyFunctionType::ExtInfo().withRepresentation(
           FunctionTypeRepresentation::Thin));
     BuiltinTypes.insert(thinFunction);