moveonly: add mp/type-void.h

Author: ryanofsky

CMakeLists.txt

@@ -60,6 +60,7 @@ set(MP_PUBLIC_HEADERS
   include/mp/type-struct.h
   include/mp/type-tuple.h
   include/mp/type-vector.h
+  include/mp/type-void.h
   include/mp/util.h)
 add_library(multiprocess STATIC
   ${MP_PROXY_SRCS}

include/mp/proxy-types.h

@@ -165,11 +165,6 @@ void ThrowField(TypeList<std::exception>, InvokeContext& invoke_context, Input&&
     throw std::runtime_error(std::string(CharCast(data.begin()), data.size()));
 }
 
-template <typename LocalType, typename Output>
-void CustomBuildField(TypeList<LocalType>, Priority<1>, InvokeContext& invoke_context, ::capnp::Void, Output&& output)
-{
-}
-
 template <typename... Values>
 bool CustomHasValue(InvokeContext& invoke_context, Values&&... value)
 {
@@ -210,11 +205,6 @@ struct ListOutput<::capnp::List<T, kind>>
     // clang-format on
 };
 
-template <typename Value>
-::capnp::Void BuildPrimitive(InvokeContext& invoke_context, Value&&, TypeList<::capnp::Void>)
-{
-    return {};
-}
 template <typename Output>
 void CustomBuildField(TypeList<std::exception>,
     Priority<1>,

include/mp/type-void.h

@@ -0,0 +1,23 @@
+// Copyright (c) 2025 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef MP_PROXY_TYPE_VOID_H
+#define MP_PROXY_TYPE_VOID_H
+
+#include <mp/util.h>
+
+namespace mp {
+template <typename Value>
+::capnp::Void BuildPrimitive(InvokeContext& invoke_context, Value&&, TypeList<::capnp::Void>)
+{
+    return {};
+}
+
+template <typename LocalType, typename Output>
+void CustomBuildField(TypeList<LocalType>, Priority<1>, InvokeContext& invoke_context, ::capnp::Void, Output&& output)
+{
+}
+} // namespace mp
+
+#endif // MP_PROXY_TYPE_VOID_H