Rename `absl::NonNull` to `absl::Nonnull`.

The current spelling is inconsistent with standard casing rules: "nonnull" is a single word, not two.

PiperOrigin-RevId: 546034114
Change-Id: I04e5a204f4a74ebaa76031dd0b0874ca9cfa902c

absl/base/internal/nullability_impl.h

@@ -60,7 +60,7 @@ struct EnableNullable {
 };
 
 template <typename T>
-struct EnableNonNull {
+struct EnableNonnull {
   static_assert(nullability_internal::IsSupportedType<std::remove_cv_t<T>>,
                 "Template argument must be a raw or supported smart pointer "
                 "type. See absl/base/nullability.h.");
@@ -86,8 +86,8 @@ using NullableImpl
 #endif
     = T;
 
-template <typename T, typename = typename EnableNonNull<T>::type>
-using NonNullImpl
+template <typename T, typename = typename EnableNonnull<T>::type>
+using NonnullImpl
 #if ABSL_HAVE_CPP_ATTRIBUTE(clang::annotate)
     [[clang::annotate("Nonnull")]]
 #endif

absl/base/nullability.h

@@ -20,7 +20,7 @@
 // expected nullability of pointers. These annotations allow you to designate
 // pointers in one of three classification states:
 //
-//  * "Non-null" (for pointers annotated `NonNull<T>`), indicating that it is
+//  * "Non-null" (for pointers annotated `Nonnull<T>`), indicating that it is
 //    invalid for the given pointer to ever be null.
 //  * "Nullable" (for pointers annotated `Nullable<T>`), indicating that it is
 //    valid for the given pointer to be null.
@@ -69,7 +69,7 @@
 //
 // It is important to note that these annotations are not distinct strong
 // *types*. They are alias templates defined to be equal to the underlying
-// pointer type. A pointer annotated `NonNull<T*>`, for example, is simply a
+// pointer type. A pointer annotated `Nonnull<T*>`, for example, is simply a
 // pointer of type `T*`. Each annotation acts as a form of documentation about
 // the contract for the given pointer. Each annotation requires providers or
 // consumers of these pointers across API boundaries to take appropriate steps
@@ -91,13 +91,13 @@
 // Example:
 //
 // // PaySalary() requires the passed pointer to an `Employee` to be non-null.
-// void PaySalary(absl::NonNull<Employee *> e) {
+// void PaySalary(absl::Nonnull<Employee *> e) {
 //   pay(e->salary);  // OK to dereference
 // }
 //
 // // CompleteTransaction() guarantees the returned pointer to an `Account` to
 // // be non-null.
-// absl::NonNull<Account *> balance CompleteTransaction(double fee) {
+// absl::Nonnull<Account *> balance CompleteTransaction(double fee) {
 // ...
 // }
 //
@@ -144,8 +144,8 @@
 // These nullability annotations are primarily a human readable signal about the
 // intended contract of the pointer. They are not *types* and do not currently
 // provide any correctness guarantees. For example, a pointer annotated as
-// `NonNull<T*>` is *not guaranteed* to be non-null, and the compiler won't
-// alert or prevent assignment of a `Nullable<T*>` to a `NonNull<T*>`.
+// `Nonnull<T*>` is *not guaranteed* to be non-null, and the compiler won't
+// alert or prevent assignment of a `Nullable<T*>` to a `Nonnull<T*>`.
 // ===========================================================================
 #ifndef ABSL_BASE_NULLABILITY_H_
 #define ABSL_BASE_NULLABILITY_H_
@@ -154,7 +154,7 @@
 
 namespace absl {
 
-// absl::NonNull
+// absl::Nonnull
 //
 // The indicated pointer is never null. It is the responsibility of the provider
 // of this pointer across an API boundary to ensure that the pointer is never be
@@ -168,7 +168,7 @@ namespace absl {
 //   pay(*employee);  // OK to dereference
 // }
 template <typename T>
-using NonNull = nullability_internal::NonNullImpl<T>;
+using Nonnull = nullability_internal::NonnullImpl<T>;
 
 // absl::Nullable
 //
@@ -195,7 +195,7 @@ using Nullable = nullability_internal::NullableImpl<T>;
 // Consumers of these pointers across an API boundary should treat such pointers
 // with the same caution they treat currently unannotated pointers. Most
 // existing code will have "unknown"  pointers, which should eventually be
-// migrated into one of the above two nullability states: `NonNull<T>` or
+// migrated into one of the above two nullability states: `Nonnull<T>` or
 //  `Nullable<T>`.
 //
 // NOTE: Because this annotation is the global default state, pointers without

absl/base/nullability_test.cc

@@ -22,73 +22,73 @@
 #include "absl/base/attributes.h"
 
 namespace {
-using ::absl::NonNull;
+using ::absl::Nonnull;
 using ::absl::NullabilityUnknown;
 using ::absl::Nullable;
 
-void funcWithNonnullArg(NonNull<int*> /*arg*/) {}
+void funcWithNonnullArg(Nonnull<int*> /*arg*/) {}
 template <typename T>
-void funcWithDeducedNonnullArg(NonNull<T*> /*arg*/) {}
+void funcWithDeducedNonnullArg(Nonnull<T*> /*arg*/) {}
 
-TEST(NonNullTest, NonNullArgument) {
+TEST(NonnullTest, NonnullArgument) {
   int var = 0;
   funcWithNonnullArg(&var);
   funcWithDeducedNonnullArg(&var);
 }
 
-NonNull<int*> funcWithNonnullReturn() {
+Nonnull<int*> funcWithNonnullReturn() {
   static int var = 0;
   return &var;
 }
 
-TEST(NonNullTest, NonNullReturn) {
+TEST(NonnullTest, NonnullReturn) {
   auto var = funcWithNonnullReturn();
   (void)var;
 }
 
 TEST(PassThroughTest, PassesThroughRawPointerToInt) {
-  EXPECT_TRUE((std::is_same<NonNull<int*>, int*>::value));
+  EXPECT_TRUE((std::is_same<Nonnull<int*>, int*>::value));
   EXPECT_TRUE((std::is_same<Nullable<int*>, int*>::value));
   EXPECT_TRUE((std::is_same<NullabilityUnknown<int*>, int*>::value));
 }
 
 TEST(PassThroughTest, PassesThroughRawPointerToVoid) {
-  EXPECT_TRUE((std::is_same<NonNull<void*>, void*>::value));
+  EXPECT_TRUE((std::is_same<Nonnull<void*>, void*>::value));
   EXPECT_TRUE((std::is_same<Nullable<void*>, void*>::value));
   EXPECT_TRUE((std::is_same<NullabilityUnknown<void*>, void*>::value));
 }
 
 TEST(PassThroughTest, PassesThroughUniquePointerToInt) {
   using T = std::unique_ptr<int>;
-  EXPECT_TRUE((std::is_same<NonNull<T>, T>::value));
+  EXPECT_TRUE((std::is_same<Nonnull<T>, T>::value));
   EXPECT_TRUE((std::is_same<Nullable<T>, T>::value));
   EXPECT_TRUE((std::is_same<NullabilityUnknown<T>, T>::value));
 }
 
 TEST(PassThroughTest, PassesThroughSharedPointerToInt) {
   using T = std::shared_ptr<int>;
-  EXPECT_TRUE((std::is_same<NonNull<T>, T>::value));
+  EXPECT_TRUE((std::is_same<Nonnull<T>, T>::value));
   EXPECT_TRUE((std::is_same<Nullable<T>, T>::value));
   EXPECT_TRUE((std::is_same<NullabilityUnknown<T>, T>::value));
 }
 
 TEST(PassThroughTest, PassesThroughSharedPointerToVoid) {
   using T = std::shared_ptr<void>;
-  EXPECT_TRUE((std::is_same<NonNull<T>, T>::value));
+  EXPECT_TRUE((std::is_same<Nonnull<T>, T>::value));
   EXPECT_TRUE((std::is_same<Nullable<T>, T>::value));
   EXPECT_TRUE((std::is_same<NullabilityUnknown<T>, T>::value));
 }
 
 TEST(PassThroughTest, PassesThroughPointerToMemberObject) {
   using T = decltype(&std::pair<int, int>::first);
-  EXPECT_TRUE((std::is_same<NonNull<T>, T>::value));
+  EXPECT_TRUE((std::is_same<Nonnull<T>, T>::value));
   EXPECT_TRUE((std::is_same<Nullable<T>, T>::value));
   EXPECT_TRUE((std::is_same<NullabilityUnknown<T>, T>::value));
 }
 
 TEST(PassThroughTest, PassesThroughPointerToMemberFunction) {
   using T = decltype(&std::unique_ptr<int>::reset);
-  EXPECT_TRUE((std::is_same<NonNull<T>, T>::value));
+  EXPECT_TRUE((std::is_same<Nonnull<T>, T>::value));
   EXPECT_TRUE((std::is_same<Nullable<T>, T>::value));
   EXPECT_TRUE((std::is_same<NullabilityUnknown<T>, T>::value));
 }