From ce865a9ba86e603e6eb69aba53f791203b80fcb2 Mon Sep 17 00:00:00 2001
From: marco <*~=`'#}+{/-|&$^_@721217.xyz>
Date: Tue, 14 Jul 2026 11:05:39 +0200
Subject: [PATCH 1/3] refactor: Directly use value in CustomBuildField

This avoids a std::span ctor.

Recommended in https://github.com/bitcoin-core/libmultiprocess/pull/305#pullrequestreview-4689778284
---
 include/mp/type-data.h | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/include/mp/type-data.h b/include/mp/type-data.h
index 09c93df9..9110be91 100644
--- a/include/mp/type-data.h
+++ b/include/mp/type-data.h
@@ -32,9 +32,8 @@ template <typename LocalType, typename Value, typename Output>
 void CustomBuildField(TypeList<LocalType>, Priority<2>, InvokeContext& invoke_context, Value&& value, Output&& output)
 requires (std::is_same_v<decltype(output.get()), ::capnp::Data::Builder> && IsByteSpan<LocalType>)
 {
-    auto data = std::span{value};
-    auto result = output.init(data.size());
-    std::ranges::copy(data, result.begin());
+    auto result = output.init(value.size());
+    std::ranges::copy(value, result.begin());
 }
 
 template <typename LocalType, typename Input, typename ReadDest>

From 17eab90b526e3fb713acbda1ec01321f2b9f2e84 Mon Sep 17 00:00:00 2001
From: marco <*~=`'#}+{/-|&$^_@721217.xyz>
Date: Tue, 14 Jul 2026 11:06:41 +0200
Subject: [PATCH 2/3] test: Fix typo in listen_tests.cpp

Recommended by the LLM in https://github.com/bitcoin/bitcoin/pull/35684#issuecomment-4916571942
---
 test/mp/test/listen_tests.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/mp/test/listen_tests.cpp b/test/mp/test/listen_tests.cpp
index 1506eaa4..24ca1652 100644
--- a/test/mp/test/listen_tests.cpp
+++ b/test/mp/test/listen_tests.cpp
@@ -225,7 +225,7 @@ KJ_TEST("ListenConnections enforces a local connection limit")
 {
     // With max-connections=1, the second socket can connect to the kernel
     // backlog, but ListenConnections should not accept or serve it until the
-    // first accepts clients disconnects.
+    // first accepted client disconnects.
 
     ListenSetup server(/*max_connections=*/1);
 

From 8226c05549b0405ebac3208751c53a03563ea745 Mon Sep 17 00:00:00 2001
From: marco <*~=`'#}+{/-|&$^_@721217.xyz>
Date: Tue, 14 Jul 2026 11:08:48 +0200
Subject: [PATCH 3/3] refactor: memcpy -> std::ranges::copy

I think there is no issue of passing a nullptr here, but it makes sense to use the std-lib copy for consistency.

Recommended in https://github.com/bitcoin-core/libmultiprocess/pull/305#pullrequestreview-4689778284
---
 include/mp/type-char.h   | 8 +++++---
 include/mp/type-string.h | 5 ++++-
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/include/mp/type-char.h b/include/mp/type-char.h
index b51ffeb1..19080b46 100644
--- a/include/mp/type-char.h
+++ b/include/mp/type-char.h
@@ -7,6 +7,9 @@
 
 #include <mp/util.h>
 
+#include <algorithm>
+#include <ranges>
+
 namespace mp {
 template <typename Output, size_t size>
 void CustomBuildField(TypeList<const unsigned char*>,
@@ -16,7 +19,7 @@ void CustomBuildField(TypeList<const unsigned char*>,
     Output&& output)
 {
     auto result = output.init(size);
-    memcpy(result.begin(), value, size);
+    std::ranges::copy(value, result.begin());
 }
 
 template <size_t size, typename Input, typename ReadDest>
@@ -27,8 +30,7 @@ decltype(auto) CustomReadField(TypeList<unsigned char[size]>,
     ReadDest&& read_dest)
 {
     return read_dest.update([&](auto& value) {
-        auto data = input.get();
-        memcpy(value, data.begin(), size);
+        std::ranges::copy(input.get(), std::ranges::begin(value));
     });
 }
 } // namespace mp
diff --git a/include/mp/type-string.h b/include/mp/type-string.h
index d4c3383b..a8275a39 100644
--- a/include/mp/type-string.h
+++ b/include/mp/type-string.h
@@ -7,6 +7,9 @@
 
 #include <mp/util.h>
 
+#include <algorithm>
+#include <ranges>
+
 namespace mp {
 template <typename Value, typename Output>
 void CustomBuildField(TypeList<std::string>,
@@ -16,7 +19,7 @@ void CustomBuildField(TypeList<std::string>,
     Output&& output)
 {
     auto result = output.init(value.size());
-    memcpy(result.begin(), value.data(), value.size());
+    std::ranges::copy(value, result.begin());
 }
 
 template <typename Input, typename ReadDest>