diff --git a/flang/include/flang/Common/idioms.h b/flang/include/flang/Common/idioms.h
--- a/flang/include/flang/Common/idioms.h
+++ b/flang/include/flang/Common/idioms.h
@@ -26,6 +26,7 @@
 #include "llvm/Support/Compiler.h"
 #include <functional>
 #include <list>
+#include <memory>
 #include <optional>
 #include <string>
 #include <tuple>
@@ -142,6 +143,14 @@
   return *p;
 }
 
+template <typename T>
+constexpr T &Deref(const std::unique_ptr<T> &p, const char *file, int line) {
+  if (!p) {
+    Fortran::common::die("nullptr dereference at %s(%d)", file, line);
+  }
+  return *p;
+}
+
 // Given a const reference to a value, return a copy of the value.
 template <typename A> A Clone(const A &x) { return x; }
 
diff --git a/flang/include/flang/Evaluate/intrinsics.h b/flang/include/flang/Evaluate/intrinsics.h
--- a/flang/include/flang/Evaluate/intrinsics.h
+++ b/flang/include/flang/Evaluate/intrinsics.h
@@ -15,6 +15,7 @@
 #include "flang/Common/default-kinds.h"
 #include "flang/Parser/char-block.h"
 #include "flang/Parser/message.h"
+#include <memory>
 #include <optional>
 #include <string>
 
@@ -64,8 +65,12 @@
 private:
   class Implementation;
 
+  IntrinsicProcTable() = default;
+
 public:
   ~IntrinsicProcTable();
+  IntrinsicProcTable(IntrinsicProcTable &&) = default;
+
   static IntrinsicProcTable Configure(
       const common::IntrinsicTypeDefaultKinds &);
 
@@ -100,7 +105,7 @@
   llvm::raw_ostream &Dump(llvm::raw_ostream &) const;
 
 private:
-  Implementation *impl_{nullptr}; // owning pointer
+  std::unique_ptr<Implementation> impl_;
 };
 
 // Check if an intrinsic explicitly allows its INTENT(OUT) arguments to be
diff --git a/flang/lib/Evaluate/intrinsics.cpp b/flang/lib/Evaluate/intrinsics.cpp
--- a/flang/lib/Evaluate/intrinsics.cpp
+++ b/flang/lib/Evaluate/intrinsics.cpp
@@ -2221,16 +2221,12 @@
   return DynamicType{category, defaults_.GetDefaultKind(category)};
 }
 
-IntrinsicProcTable::~IntrinsicProcTable() {
-  // Discard the configured tables.
-  delete impl_;
-  impl_ = nullptr;
-}
+IntrinsicProcTable::~IntrinsicProcTable() = default;
 
 IntrinsicProcTable IntrinsicProcTable::Configure(
     const common::IntrinsicTypeDefaultKinds &defaults) {
   IntrinsicProcTable result;
-  result.impl_ = new IntrinsicProcTable::Implementation(defaults);
+  result.impl_ = std::make_unique<IntrinsicProcTable::Implementation>(defaults);
   return result;
 }