moveonly: add mp/type-decay.h

Author: ryanofsky

CMakeLists.txt

@@ -47,6 +47,7 @@ set(MP_PUBLIC_HEADERS
   include/mp/proxy.h
   include/mp/type-char.h
   include/mp/type-context.h
+  include/mp/type-decay.h
   include/mp/type-exception.h
   include/mp/type-function.h
   include/mp/type-interface.h

example/types.h

@@ -6,6 +6,7 @@
 #define EXAMPLE_TYPES_H
 
 #include <mp/type-context.h>
+#include <mp/type-decay.h>
 #include <mp/type-interface.h>
 #include <mp/type-string.h>
 

include/mp/proxy-types.h

@@ -205,32 +205,6 @@ struct ListOutput<::capnp::List<T, kind>>
     // clang-format on
 };
 
-template <typename LocalType, typename Value, typename Output>
-void CustomBuildField(TypeList<const LocalType>,
-    Priority<0>,
-    InvokeContext& invoke_context,
-    Value&& value,
-    Output&& output)
-{
-    BuildField(TypeList<LocalType>(), invoke_context, output, std::forward<Value>(value));
-}
-
-template <typename LocalType, typename Value, typename Output>
-void CustomBuildField(TypeList<LocalType&>, Priority<0>, InvokeContext& invoke_context, Value&& value, Output&& output)
-{
-    BuildField(TypeList<LocalType>(), invoke_context, output, std::forward<Value>(value));
-}
-
-template <typename LocalType, typename Value, typename Output>
-void CustomBuildField(TypeList<LocalType&&>,
-    Priority<0>,
-    InvokeContext& invoke_context,
-    Value&& value,
-    Output&& output)
-{
-    BuildField(TypeList<LocalType>(), invoke_context, output, std::forward<Value>(value));
-}
-
 template <typename LocalType, typename Value, typename Output>
 void CustomBuildField(TypeList<LocalType>, Priority<0>, InvokeContext& invoke_context, Value&& value, Output&& output)
 {

include/mp/type-decay.h

@@ -0,0 +1,38 @@
+// 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_DECAY_H
+#define MP_PROXY_TYPE_DECAY_H
+
+#include <mp/util.h>
+
+namespace mp {
+template <typename LocalType, typename Value, typename Output>
+void CustomBuildField(TypeList<const LocalType>,
+    Priority<0>,
+    InvokeContext& invoke_context,
+    Value&& value,
+    Output&& output)
+{
+    BuildField(TypeList<LocalType>(), invoke_context, output, std::forward<Value>(value));
+}
+
+template <typename LocalType, typename Value, typename Output>
+void CustomBuildField(TypeList<LocalType&>, Priority<0>, InvokeContext& invoke_context, Value&& value, Output&& output)
+{
+    BuildField(TypeList<LocalType>(), invoke_context, output, std::forward<Value>(value));
+}
+
+template <typename LocalType, typename Value, typename Output>
+void CustomBuildField(TypeList<LocalType&&>,
+    Priority<0>,
+    InvokeContext& invoke_context,
+    Value&& value,
+    Output&& output)
+{
+    BuildField(TypeList<LocalType>(), invoke_context, output, std::forward<Value>(value));
+}
+} // namespace mp
+
+#endif // MP_PROXY_TYPE_DECAY_H

test/mp/test/foo-types.h

@@ -7,6 +7,7 @@
 
 #include <mp/proxy-types.h>
 #include <mp/type-context.h>
+#include <mp/type-decay.h>
 #include <mp/type-interface.h>
 #include <mp/type-map.h>
 #include <mp/type-message.h>