Remove unused `serialized_message_internal.h` which was left after the old
version of `SerializedMessageReader`.

PiperOrigin-RevId: 911936819
diff --git a/riegeli/messages/serialized_message_internal.h b/riegeli/messages/serialized_message_internal.h
deleted file mode 100644
index d13702e..0000000
--- a/riegeli/messages/serialized_message_internal.h
+++ /dev/null
@@ -1,179 +0,0 @@
-// Copyright 2025 Google LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#ifndef RIEGELI_MESSAGES_SERIALIZED_MESSAGE_INTERNAL_
-#define RIEGELI_MESSAGES_SERIALIZED_MESSAGE_INTERNAL_
-
-#include <stddef.h>
-#include <stdint.h>
-
-#include <functional>
-#include <type_traits>
-#include <utility>
-
-#include "absl/base/attributes.h"
-#include "absl/status/status.h"
-#include "riegeli/base/type_erased_ref.h"
-
-namespace riegeli {
-
-class LimitingReaderBase;
-class SerializedMessageWriter;
-
-namespace serialized_message_internal {
-
-template <typename Enable, typename Context, typename Action, typename... Args>
-struct IsInvocableWithContextImpl : std::false_type {};
-
-template <typename Context, typename Action, typename... Args>
-struct IsInvocableWithContextImpl<std::enable_if_t<!std::is_void_v<Context>>,
-                                  Context, Action, Args...>
-    : std::is_invocable_r<absl::Status, Action, Args..., Context&> {};
-
-template <typename Context, typename Action, typename... Args>
-struct IsInvocableWithContext
-    : IsInvocableWithContextImpl<void, Context, Action, Args...> {};
-
-template <typename Action, typename... Args>
-struct IsInvocableWithoutContext
-    : std::is_invocable_r<absl::Status, Action, Args...> {};
-
-template <typename Context, typename Action, typename... Args>
-struct IsAction
-    : std::disjunction<IsInvocableWithContext<Context, Action, Args...>,
-                       IsInvocableWithoutContext<Action, Args...>> {};
-
-template <typename Context, typename Action, typename... Args,
-          std::enable_if_t<
-              IsInvocableWithContext<Context, Action, Args...>::value, int> = 0>
-inline absl::Status InvokeAction(TypeErasedRef context, Action&& action,
-                                 Args&&... args) {
-  return std::invoke(std::forward<Action>(action), std::forward<Args>(args)...,
-                     context.Cast<Context&>());
-}
-
-template <typename Context, typename Action, typename... Args,
-          std::enable_if_t<IsInvocableWithoutContext<Action, Args...>::value,
-                           int> = 0>
-inline absl::Status InvokeAction(ABSL_ATTRIBUTE_UNUSED TypeErasedRef context,
-                                 Action&& action, Args&&... args) {
-  return std::invoke(std::forward<Action>(action), std::forward<Args>(args)...);
-}
-
-template <typename Context, typename Action, typename... Args>
-struct IsActionWithSrc
-    : IsAction<Context, Action, Args..., LimitingReaderBase&> {};
-
-template <typename Context, typename Action, typename... Args>
-struct IsActionWithoutSrc : IsAction<Context, Action, Args...> {};
-
-template <typename Context, typename Action, typename... Args>
-struct IsActionWithOptionalSrc
-    : std::disjunction<IsActionWithSrc<Context, Action, Args...>,
-                       IsActionWithoutSrc<Context, Action, Args...>> {};
-
-template <
-    typename Context, typename Action, typename... Args,
-    std::enable_if_t<IsActionWithSrc<Context, Action, Args...>::value, int> = 0>
-inline absl::Status InvokeActionWithSrc(LimitingReaderBase& src,
-                                        TypeErasedRef context, Action&& action,
-                                        Args&&... args) {
-  return InvokeAction<Context>(context, std::forward<Action>(action),
-                               std::forward<Args>(args)..., src);
-}
-
-template <typename Context, typename Action, typename... Args,
-          std::enable_if_t<IsActionWithoutSrc<Context, Action, Args...>::value,
-                           int> = 0>
-inline absl::Status InvokeActionWithSrc(
-    ABSL_ATTRIBUTE_UNUSED LimitingReaderBase& src, TypeErasedRef context,
-    Action&& action, Args&&... args) {
-  return InvokeAction<Context>(context, std::forward<Action>(action),
-                               std::forward<Args>(args)...);
-}
-
-template <typename Context, typename Action, typename... Args>
-struct IsActionWithDest
-    : IsAction<Context, Action, Args..., SerializedMessageWriter&> {};
-
-template <typename Context, typename Action, typename... Args>
-struct IsActionWithoutDest : IsAction<Context, Action, Args...> {};
-
-template <typename Context, typename Action, typename... Args>
-struct IsActionWithOptionalDest
-    : std::disjunction<IsActionWithDest<Context, Action, Args...>,
-                       IsActionWithoutDest<Context, Action, Args...>> {};
-
-template <typename Context, typename Action, typename... Args,
-          std::enable_if_t<IsActionWithDest<Context, Action, Args...>::value,
-                           int> = 0>
-inline absl::Status InvokeActionWithDest(SerializedMessageWriter& dest,
-                                         TypeErasedRef context, Action&& action,
-                                         Args&&... args) {
-  return InvokeAction<Context>(context, std::forward<Action>(action),
-                               std::forward<Args>(args)..., dest);
-}
-
-template <typename Context, typename Action, typename... Args,
-          std::enable_if_t<IsActionWithoutDest<Context, Action, Args...>::value,
-                           int> = 0>
-inline absl::Status InvokeActionWithDest(
-    ABSL_ATTRIBUTE_UNUSED SerializedMessageWriter& dest, TypeErasedRef context,
-    Action&& action, Args&&... args) {
-  return InvokeAction<Context>(context, std::forward<Action>(action),
-                               std::forward<Args>(args)...);
-}
-
-template <typename Context, typename Action, typename... Args>
-struct IsActionWithRequiredSrcAndOptionalDest
-    : IsActionWithOptionalDest<Context, Action, Args..., LimitingReaderBase&> {
-};
-
-template <typename Context, typename Action, typename... Args>
-struct IsActionWithOptionalSrcAndDest
-    : std::disjunction<
-          IsActionWithRequiredSrcAndOptionalDest<Context, Action, Args...>,
-          IsActionWithOptionalDest<Context, Action, Args...>> {};
-
-template <typename Context, typename Action, typename... Args,
-          std::enable_if_t<IsActionWithRequiredSrcAndOptionalDest<
-                               Context, Action, Args...>::value,
-                           int> = 0>
-inline absl::Status InvokeActionWithSrcAndDest(LimitingReaderBase& src,
-                                               SerializedMessageWriter& dest,
-                                               TypeErasedRef context,
-                                               Action&& action,
-                                               Args&&... args) {
-  return InvokeActionWithDest<Context>(dest, context,
-                                       std::forward<Action>(action),
-                                       std::forward<Args>(args)..., src);
-}
-
-template <
-    typename Context, typename Action, typename... Args,
-    std::enable_if_t<IsActionWithOptionalDest<Context, Action, Args...>::value,
-                     int> = 0>
-inline absl::Status InvokeActionWithSrcAndDest(
-    ABSL_ATTRIBUTE_UNUSED LimitingReaderBase& src,
-    SerializedMessageWriter& dest, TypeErasedRef context, Action&& action,
-    Args&&... args) {
-  return InvokeActionWithDest<Context>(
-      dest, context, std::forward<Action>(action), std::forward<Args>(args)...);
-}
-
-}  // namespace serialized_message_internal
-
-}  // namespace riegeli
-
-#endif  // RIEGELI_MESSAGES_SERIALIZED_MESSAGE_INTERNAL_