1 files changed, 43 insertions, 0 deletions
diff --git a/pw_function/public/pw_function/internal/static_invoker.h b/pw_function/public/pw_function/internal/static_invoker.h
new file mode 100644
index 000000000..73605af34
--- /dev/null
+++ b/pw_function/public/pw_function/internal/static_invoker.h
@@ -0,0 +1,43 @@
+// Copyright 2023 The Pigweed Authors
+//
+// 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
+//
+//     https://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.
+#pragma once
+
+// This code is in its own header since Doxygen / Breathe can't parse it.
+
+namespace pw::function::internal {
+
+template <typename FunctionType, typename CallOperatorType>
+struct StaticInvoker;
+
+template <typename FunctionType, typename Return, typename... Args>
+struct StaticInvoker<FunctionType, Return (FunctionType::*)(Args...)> {
+  // Invoker function with the context argument last to match libc. Could add a
+  // version with the context first if needed.
+  static Return InvokeWithContextLast(Args... args, void* context) {
+    return static_cast<FunctionType*>(context)->operator()(
+        std::forward<Args>(args)...);
+  }
+
+  static Return InvokeWithContextFirst(void* context, Args... args) {
+    return static_cast<FunctionType*>(context)->operator()(
+        std::forward<Args>(args)...);
+  }
+};
+
+// Make the const version identical to the non-const version.
+template <typename FunctionType, typename Return, typename... Args>
+struct StaticInvoker<FunctionType, Return (FunctionType::*)(Args...) const>
+    : StaticInvoker<FunctionType, Return (FunctionType::*)(Args...)> {};
+
+}  // namespace pw::function::internal