moveonly: add mp/type-tuple.h

Author: ryanofsky

CMakeLists.txt

@@ -51,6 +51,7 @@ set(MP_PUBLIC_HEADERS
   include/mp/type-pair.h
   include/mp/type-pointer.h
   include/mp/type-set.h
+  include/mp/type-tuple.h
   include/mp/type-vector.h
   include/mp/util.h)
 add_library(multiprocess STATIC

include/mp/proxy-types.h

@@ -141,28 +141,6 @@ struct ReadDestUpdate
     Value& m_value;
 };
 
-
-
-
-// TODO: Should generalize this to work with arbitrary length tuples, not just length 2-tuples.
-template <typename KeyLocalType, typename ValueLocalType, typename Input, typename ReadDest>
-decltype(auto) CustomReadField(TypeList<std::tuple<KeyLocalType, ValueLocalType>>,
-    Priority<1>,
-    InvokeContext& invoke_context,
-    Input&& input,
-    ReadDest&& read_dest)
-{
-    return read_dest.update([&](auto& value) {
-        const auto& pair = input.get();
-        using Struct = ProxyStruct<typename Decay<decltype(pair)>::Reads>;
-        using Accessors = typename Struct::Accessors;
-        ReadField(TypeList<KeyLocalType>(), invoke_context, Make<StructField, std::tuple_element_t<0, Accessors>>(pair),
-            ReadDestUpdate(std::get<0>(value)));
-        ReadField(TypeList<ValueLocalType>(), invoke_context, Make<StructField, std::tuple_element_t<1, Accessors>>(pair),
-            ReadDestUpdate(std::get<1>(value)));
-    });
-}
-
 template <typename LocalType, typename Input, typename ReadDest>
 decltype(auto) CustomReadField(TypeList<LocalType>,
     Priority<1>,
@@ -584,20 +562,6 @@ void CustomBuildField(TypeList<std::exception>,
 {
     BuildField(TypeList<std::string>(), invoke_context, output, std::string(value.what()));
 }
-// TODO: Should generalize this to work with arbitrary length tuples, not just length 2-tuples.
-template <typename KeyLocalType, typename ValueLocalType, typename Value, typename Output>
-void CustomBuildField(TypeList<std::tuple<KeyLocalType, ValueLocalType>>,
-    Priority<1>,
-    InvokeContext& invoke_context,
-    Value&& value,
-    Output&& output)
-{
-    auto pair = output.init();
-    using Accessors = typename ProxyStruct<typename decltype(pair)::Builds>::Accessors;
-    BuildField(TypeList<KeyLocalType>(), invoke_context, Make<StructField, std::tuple_element_t<0, Accessors>>(pair), std::get<0>(value));
-    BuildField(TypeList<ValueLocalType>(), invoke_context, Make<StructField, std::tuple_element_t<1, Accessors>>(pair), std::get<1>(value));
-}
-
 template <typename LocalType, typename Value, typename Output>
 void CustomBuildField(TypeList<const LocalType>,
     Priority<0>,

include/mp/type-tuple.h

@@ -0,0 +1,45 @@
+// 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_TUPLE_H
+#define MP_PROXY_TYPE_TUPLE_H
+
+#include <mp/util.h>
+
+namespace mp {
+// TODO: Should generalize this to work with arbitrary length tuples, not just length 2-tuples.
+template <typename KeyLocalType, typename ValueLocalType, typename Value, typename Output>
+void CustomBuildField(TypeList<std::tuple<KeyLocalType, ValueLocalType>>,
+    Priority<1>,
+    InvokeContext& invoke_context,
+    Value&& value,
+    Output&& output)
+{
+    auto pair = output.init();
+    using Accessors = typename ProxyStruct<typename decltype(pair)::Builds>::Accessors;
+    BuildField(TypeList<KeyLocalType>(), invoke_context, Make<StructField, std::tuple_element_t<0, Accessors>>(pair), std::get<0>(value));
+    BuildField(TypeList<ValueLocalType>(), invoke_context, Make<StructField, std::tuple_element_t<1, Accessors>>(pair), std::get<1>(value));
+}
+
+// TODO: Should generalize this to work with arbitrary length tuples, not just length 2-tuples.
+template <typename KeyLocalType, typename ValueLocalType, typename Input, typename ReadDest>
+decltype(auto) CustomReadField(TypeList<std::tuple<KeyLocalType, ValueLocalType>>,
+    Priority<1>,
+    InvokeContext& invoke_context,
+    Input&& input,
+    ReadDest&& read_dest)
+{
+    return read_dest.update([&](auto& value) {
+        const auto& pair = input.get();
+        using Struct = ProxyStruct<typename Decay<decltype(pair)>::Reads>;
+        using Accessors = typename Struct::Accessors;
+        ReadField(TypeList<KeyLocalType>(), invoke_context, Make<StructField, std::tuple_element_t<0, Accessors>>(pair),
+            ReadDestUpdate(std::get<0>(value)));
+        ReadField(TypeList<ValueLocalType>(), invoke_context, Make<StructField, std::tuple_element_t<1, Accessors>>(pair),
+            ReadDestUpdate(std::get<1>(value)));
+    });
+}
+} // namespace mp
+
+#endif // MP_PROXY_TYPE_TUPLE_H