diff --git a/mlir/examples/toy/Ch5/mlir/LowerToAffineLoops.cpp b/mlir/examples/toy/Ch5/mlir/LowerToAffineLoops.cpp
--- a/mlir/examples/toy/Ch5/mlir/LowerToAffineLoops.cpp
+++ b/mlir/examples/toy/Ch5/mlir/LowerToAffineLoops.cpp
@@ -297,7 +297,7 @@
 
   // Now that the conversion target has been defined, we just need to provide
   // the set of patterns that will lower the Toy operations.
-  OwningRewritePatternList patterns;
+  OwningRewritePatternList patterns(&getContext());
   patterns.insert<AddOpLowering, ConstantOpLowering, MulOpLowering,
                   ReturnOpLowering, TransposeOpLowering>(&getContext());
 
diff --git a/mlir/examples/toy/Ch6/mlir/LowerToAffineLoops.cpp b/mlir/examples/toy/Ch6/mlir/LowerToAffineLoops.cpp
--- a/mlir/examples/toy/Ch6/mlir/LowerToAffineLoops.cpp
+++ b/mlir/examples/toy/Ch6/mlir/LowerToAffineLoops.cpp
@@ -296,7 +296,7 @@
 
   // Now that the conversion target has been defined, we just need to provide
   // the set of patterns that will lower the Toy operations.
-  OwningRewritePatternList patterns;
+  OwningRewritePatternList patterns(&getContext());
   patterns.insert<AddOpLowering, ConstantOpLowering, MulOpLowering,
                   ReturnOpLowering, TransposeOpLowering>(&getContext());
 
diff --git a/mlir/examples/toy/Ch6/mlir/LowerToLLVM.cpp b/mlir/examples/toy/Ch6/mlir/LowerToLLVM.cpp
--- a/mlir/examples/toy/Ch6/mlir/LowerToLLVM.cpp
+++ b/mlir/examples/toy/Ch6/mlir/LowerToLLVM.cpp
@@ -191,9 +191,9 @@
   // lowerings. Transitive lowering, or A->B->C lowering, is when multiple
   // patterns must be applied to fully transform an illegal operation into a
   // set of legal ones.
-  OwningRewritePatternList patterns;
-  populateAffineToStdConversionPatterns(patterns, &getContext());
-  populateLoopToStdConversionPatterns(patterns, &getContext());
+  OwningRewritePatternList patterns(&getContext());
+  populateAffineToStdConversionPatterns(patterns);
+  populateLoopToStdConversionPatterns(patterns);
   populateStdToLLVMConversionPatterns(typeConverter, patterns);
 
   // The only remaining operation to lower from the `toy` dialect, is the
diff --git a/mlir/examples/toy/Ch7/mlir/LowerToAffineLoops.cpp b/mlir/examples/toy/Ch7/mlir/LowerToAffineLoops.cpp
--- a/mlir/examples/toy/Ch7/mlir/LowerToAffineLoops.cpp
+++ b/mlir/examples/toy/Ch7/mlir/LowerToAffineLoops.cpp
@@ -297,7 +297,7 @@
 
   // Now that the conversion target has been defined, we just need to provide
   // the set of patterns that will lower the Toy operations.
-  OwningRewritePatternList patterns;
+  OwningRewritePatternList patterns(&getContext());
   patterns.insert<AddOpLowering, ConstantOpLowering, MulOpLowering,
                   ReturnOpLowering, TransposeOpLowering>(&getContext());
 
diff --git a/mlir/examples/toy/Ch7/mlir/LowerToLLVM.cpp b/mlir/examples/toy/Ch7/mlir/LowerToLLVM.cpp
--- a/mlir/examples/toy/Ch7/mlir/LowerToLLVM.cpp
+++ b/mlir/examples/toy/Ch7/mlir/LowerToLLVM.cpp
@@ -191,9 +191,9 @@
   // lowerings. Transitive lowering, or A->B->C lowering, is when multiple
   // patterns must be applied to fully transform an illegal operation into a
   // set of legal ones.
-  OwningRewritePatternList patterns;
-  populateAffineToStdConversionPatterns(patterns, &getContext());
-  populateLoopToStdConversionPatterns(patterns, &getContext());
+  OwningRewritePatternList patterns(&getContext());
+  populateAffineToStdConversionPatterns(patterns);
+  populateLoopToStdConversionPatterns(patterns);
   populateStdToLLVMConversionPatterns(typeConverter, patterns);
 
   // The only remaining operation to lower from the `toy` dialect, is the