refactor: auto-merge symbol fields via Boost.Describe

include/mrdocs/Metadata/Name.hpp

@@ -89,6 +89,11 @@ tag_invoke(
     tag_invoke(dom::ValueFromTag{}, v, *I, domCorpus);
 }
 
+/** Merge two Name metadata objects.
+*/
+void
+merge(Name& I, Name&& Other);
+
 } // mrdocs
 
 #endif

include/mrdocs/Metadata/Symbol/ExtractionMode.hpp

@@ -96,6 +96,17 @@ mostSpecific(ExtractionMode const a, ExtractionMode const b) noexcept
             std::max(static_cast<IT>(a), static_cast<IT>(b)));
 }
 
+/** Merge two ExtractionMode values.
+
+    Takes the least specific (most conservative) of the two,
+    so that a symbol demoted in any TU stays demoted.
+*/
+inline void
+merge(ExtractionMode& dst, ExtractionMode&& src) noexcept
+{
+    dst = leastSpecific(dst, src);
+}
+
 } // mrdocs
 
 #endif // MRDOCS_API_METADATA_SYMBOL_EXTRACTIONMODE_HPP

include/mrdocs/Metadata/Symbol/Friend.hpp

@@ -14,6 +14,7 @@
 #include <mrdocs/Metadata/Symbol.hpp>
 #include <mrdocs/Metadata/Symbol/Source.hpp>
 #include <mrdocs/Metadata/Type.hpp>
+#include <vector>
 
 namespace mrdocs {
 
@@ -42,12 +43,21 @@ struct FriendInfo final
     Optional<Polymorphic<struct Type>> Type = std::nullopt;
 };
 
-MRDOCS_DECL
 /** Merge another FriendInfo into this one.
 */
+MRDOCS_DECL
 void
 merge(FriendInfo& I, FriendInfo&& Other);
 
+/** Merge friend declarations, deduplicating by symbol ID.
+
+    @param dst The destination.
+    @param src The source (moved from).
+*/
+MRDOCS_DECL
+void
+merge(std::vector<FriendInfo>& dst, std::vector<FriendInfo>&& src);
+
 /** Map a FriendInfo to a dom::Object.
 
     @param t The tag type.

include/mrdocs/Metadata/Symbol/Param.hpp

@@ -18,6 +18,7 @@
 #include <mrdocs/ADT/Optional.hpp>
 #include <mrdocs/ADT/Polymorphic.hpp>
 #include <mrdocs/Metadata/Type.hpp>
+#include <vector>
 #include <string>
 
 namespace mrdocs {
@@ -68,6 +69,15 @@ MRDOCS_DECL
 void
 merge(Param& I, Param&& Other);
 
+/** Merge parameters element-wise, appending extras from `src`.
+
+    @param dst The destination.
+    @param src The source (moved from).
+*/
+MRDOCS_DECL
+void
+merge(std::vector<Param>& dst, std::vector<Param>&& src);
+
 /** Return the Param as a @ref dom::Value object.
 */
 MRDOCS_DECL

src/lib/Metadata/Info.cpp

@@ -11,6 +11,8 @@
 //
 
 #include <lib/Support/Radix.hpp>
+#include <lib/Support/Reflection/MergeReflectedType.hpp>
+#include <lib/Support/Reflection/Reflection.hpp>
 #include <mrdocs/Dom/LazyArray.hpp>
 #include <mrdocs/Dom/LazyObject.hpp>
 #include <mrdocs/Metadata.hpp>
@@ -41,30 +43,7 @@ void
 merge(Symbol& I, Symbol&& Other)
 {
     MRDOCS_ASSERT(I.id);
-    merge(I.Loc, std::move(Other.Loc));
-    if (I.Name == "")
-    {
-        I.Name = Other.Name;
-    }
-    if (I.Parent)
-    {
-        I.Parent = Other.Parent;
-    }
-    if (I.Access == AccessKind::None)
-    {
-        I.Access = Other.Access;
-    }
-    I.Extraction = leastSpecific(I.Extraction, Other.Extraction);
-
-    // Append docs
-    if (!I.doc)
-    {
-        I.doc = std::move(Other.doc);
-    }
-    else if (Other.doc)
-    {
-        merge(*I.doc, std::move(*Other.doc));
-    }
+    mergeReflected(I, Other);
 }
 
 } // mrdocs

src/lib/Metadata/Name.cpp

@@ -11,6 +11,8 @@
 //
 
 #include <lib/Support/Reflection/MapReflectedType.hpp>
+#include <lib/Support/Reflection/MergeReflectedType.hpp>
+#include <lib/Support/Reflection/Reflection.hpp>
 #include <mrdocs/Dom/LazyArray.hpp>
 #include <mrdocs/Dom/LazyObject.hpp>
 #include <mrdocs/Metadata/DomCorpus.hpp>
@@ -176,4 +178,10 @@ tag_invoke(
     v = dom::LazyObject(I, domCorpus);
 }
 
+void
+merge(Name& I, Name&& Other)
+{
+    mergeReflected(I, Other);
+}
+
 } // mrdocs

src/lib/Metadata/Symbol/Concept.cpp

@@ -9,9 +9,10 @@
 // Official repository: https://github.com/cppalliance/mrdocs
 //
 
+#include <lib/Support/Reflection/MergeReflectedType.hpp>
+#include <lib/Support/Reflection/Reflection.hpp>
 #include <mrdocs/Platform.hpp>
 #include <mrdocs/Metadata/Symbol/Concept.hpp>
-#include <llvm/ADT/STLExtras.h>
 
 namespace mrdocs {
 
@@ -62,15 +63,7 @@ void
 merge(ConceptSymbol& I, ConceptSymbol&& Other)
 {
     MRDOCS_ASSERT(canMerge(I, Other));
-    merge(I.asInfo(), std::move(Other.asInfo()));
-    if (I.Constraint.Written.empty())
-    {
-        I.Constraint = std::move(Other.Constraint);
-    }
-    if (!I.Template)
-    {
-        I.Template = std::move(Other.Template);
-    }
+    mergeReflected(I, Other);
 }
 
 } // mrdocs

src/lib/Metadata/Symbol/Enum.cpp

@@ -9,45 +9,18 @@
 // Official repository: https://github.com/cppalliance/mrdocs
 //
 
+#include <lib/Support/Reflection/MergeReflectedType.hpp>
+#include <lib/Support/Reflection/Reflection.hpp>
 #include <mrdocs/Platform.hpp>
 #include <mrdocs/Metadata/Symbol/Enum.hpp>
-#include <llvm/ADT/STLExtras.h>
 
 namespace mrdocs {
 
-namespace {
-
-void
-reduceSymbolIDs(
-    std::vector<SymbolID>& list,
-    std::vector<SymbolID>&& otherList)
-{
-    for(auto const& id : otherList)
-    {
-        if (auto it = llvm::find(list, id); it != list.end())
-        {
-            continue;
-        }
-        list.push_back(id);
-    }
-}
-
-} // (anon)
-
 void
 merge(EnumSymbol& I, EnumSymbol&& Other)
 {
     MRDOCS_ASSERT(canMerge(I, Other));
-    merge(I.asInfo(), std::move(Other.asInfo()));
-    if (!I.Scoped)
-    {
-        I.Scoped = Other.Scoped;
-    }
-    if (!I.UnderlyingType)
-    {
-        I.UnderlyingType = std::move(Other.UnderlyingType);
-    }
-    reduceSymbolIDs(I.Constants, std::move(Other.Constants));
+    mergeReflected(I, Other);
 }
 
 } // mrdocs

src/lib/Metadata/Symbol/EnumConstant.cpp

@@ -9,21 +9,18 @@
 // Official repository: https://github.com/cppalliance/mrdocs
 //
 
+#include <lib/Support/Reflection/MergeReflectedType.hpp>
+#include <lib/Support/Reflection/Reflection.hpp>
 #include <mrdocs/Platform.hpp>
 #include <mrdocs/Metadata/Symbol/EnumConstant.hpp>
-#include <llvm/ADT/STLExtras.h>
 
 namespace mrdocs {
 
 void
 merge(EnumConstantSymbol& I, EnumConstantSymbol&& Other)
 {
     MRDOCS_ASSERT(canMerge(I, Other));
-    merge(I.asInfo(), std::move(Other.asInfo()));
-    if (I.Initializer.Written.empty())
-    {
-        I.Initializer = std::move(Other.Initializer);
-    }
+    mergeReflected(I, Other);
 }
 
 } // mrdocs

src/lib/Metadata/Symbol/Friend.cpp

@@ -5,26 +5,40 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // Copyright (c) 2025 Alan de Freitas (alandefreitas@gmail.com)
+// Copyright (c) 2026 Gennaro Prota (gennaro.prota@gmail.com)
 //
 // Official repository: https://github.com/cppalliance/mrdocs
 //
 
+#include <lib/Support/Reflection/MergeReflectedType.hpp>
+#include <lib/Support/Reflection/Reflection.hpp>
 #include <mrdocs/Platform.hpp>
 #include <mrdocs/Metadata/Symbol/Friend.hpp>
-#include <llvm/ADT/STLExtras.h>
+#include <algorithm>
+#include <vector>
 
 namespace mrdocs {
 
 void
 merge(FriendInfo& I, FriendInfo&& Other)
 {
-    if (!I.id)
-    {
-        I.id = Other.id;
-    }
-    if (!I.Type)
+    mergeReflected(I, Other);
+}
+
+void
+merge(
+    std::vector<FriendInfo>& dst,
+    std::vector<FriendInfo>&& src)
+{
+    for (FriendInfo const& F : src)
     {
-        I.Type = std::move(Other.Type);
+        auto it = std::ranges::find_if(dst, [&F](auto const& other) {
+            return F.id == other.id;
+        });
+        if (it == dst.end())
+        {
+            dst.push_back(F);
+        }
     }
 }