[Fixit] Suggested by Dmitri, adding & instead of [] to bridge T and UnsafePointer<T>.

Author: nkcsgexi

lib/Sema/CSDiag.cpp

@@ -3480,8 +3480,7 @@ bool FailureDiagnosis::diagnoseContextualConversionError() {
   // When converting from T to [T] or UnsafePointer<T>, we can offer fixit to wrap
   // the expr with brackets.
   if (auto *contextDecl = contextualType->getAnyNominal()) {
-    if (contextDecl == CS->TC.Context.getArrayDecl() ||
-        contextDecl == CS->TC.Context.getUnsafePointerDecl()) {
+    if (contextDecl == CS->TC.Context.getArrayDecl()) {
       SmallVector<Type, 4> scratch;
       for (Type arg : contextualType->getAllGenericArgs(scratch)) {
         if (arg->isEqual(exprType)) {
@@ -3492,6 +3491,15 @@ bool FailureDiagnosis::diagnoseContextualConversionError() {
           return true;
         }
       }
+    } else if (contextDecl == CS->TC.Context.getUnsafePointerDecl()) {
+      SmallVector<Type, 4> scratch;
+      for (Type arg : contextualType->getAllGenericArgs(scratch)) {
+        if (arg->isEqual(exprType)) {
+          diagnose(expr->getLoc(), diagID, exprType, contextualType).
+            fixItInsert(expr->getStartLoc(), "&");
+          return true;
+        }
+      }
     }
   }
 

test/Sema/diag_type_conversion.swift

@@ -4,5 +4,7 @@ func foo1(_ a: [Int]) {}
 func foo2(_ a : UnsafePointer<Int>) {}
 func foo3 () {
   foo1(1) // expected-error {{cannot convert value of type 'Int' to expected argument type '[Int]'}} {{8-8=[}} {{9-9=]}}
-  foo2(1) // expected-error {{cannot convert value of type 'Int' to expected argument type 'UnsafePointer<Int>'}} {{8-8=[}} {{9-9=]}}
+  foo2(1) // expected-error {{cannot convert value of type 'Int' to expected argument type 'UnsafePointer<Int>'}} {{8-8=&}}
+  var j = 3
+  foo2(j) // expected-error {{cannot convert value of type 'Int' to expected argument type 'UnsafePointer<Int>'}} {{8-8=&}}
 }