fix: UsingSymbol is SymbolParent

include/mrdocs/Metadata/Symbol/Using.hpp

@@ -174,6 +174,15 @@ tag_invoke(
     v = dom::LazyObject(I, domCorpus);
 }
 
+inline
+auto&
+allMembers(UsingSymbol const& T)
+{
+    return T.ShadowDeclarations;
+}
+
+static_assert(SymbolParent<UsingSymbol>);
+
 } // mrdocs
 
 #endif // MRDOCS_API_METADATA_SYMBOL_USING_HPP

src/lib/AST/ASTVisitor.cpp

@@ -1904,6 +1904,13 @@ addMember(OverloadsSymbol& I, Symbol const& Member) const
         I.Name);
 }
 
+void
+ASTVisitor::
+addMember(UsingSymbol& I, Symbol const& Member) const
+{
+    addMember(I.ShadowDeclarations, Member);
+}
+
 void
 ASTVisitor::
 addMember(std::vector<SymbolID>& container, Symbol const& Member) const

src/lib/AST/ASTVisitor.hpp

@@ -759,6 +759,9 @@ class ASTVisitor
     void
     addMember(OverloadsSymbol& I, Symbol const& Member) const;
 
+    void
+    addMember(UsingSymbol& I, Symbol const& Member) const;
+
     void
     addMember(std::vector<SymbolID>& container, Symbol const& Member) const;
 

src/lib/Gen/hbs/MultiPageVisitor.cpp

@@ -68,6 +68,7 @@ operator()(T const& I)
         // ===================================
         // Traverse the symbol members
         // ===================================
+        MRDOCS_CHECK_OR_VOID(!I.isUsing());
         Corpus::TraverseOptions opts = {.skipInherited = std::same_as<T, RecordSymbol>};
         corpus_.traverse(opts, I, *this);
     });

src/lib/Gen/hbs/SinglePageVisitor.cpp

@@ -38,6 +38,7 @@ operator()(T const& I)
             }
         });
     }
+    MRDOCS_CHECK_OR_VOID(!I.isUsing());
     Corpus::TraverseOptions opts = {.skipInherited = std::same_as<T, RecordSymbol>};
     corpus_.traverse(opts, I, *this);
 }

src/lib/Support/LegibleNames.cpp

@@ -291,8 +291,26 @@ class LegibleNames::Impl
         MRDOCS_ASSERT(corpus_.exists(id));
 
         // Find the legible name information for this symbol
-        auto const it = map_.find(id);
-        MRDOCS_ASSERT(it != map_.end());
+        auto it = map_.find(id);
+        if (it == map_.end())
+        {
+            // Late-build a legible name for this symbol.
+            // NOTE: This may not perfectly disambiguate against siblings
+            // because the per-scope disambiguation_map_ is ephemeral,
+            // but it avoids a hard crash and produces a stable name.
+            Symbol const& I = corpus_.get(id);
+            auto const raw = getRawUnqualified(I);
+            buildLegibleMember(I, raw);
+            it = map_.find(I.id);
+            if (it == map_.end())
+            {
+                // Final, robust fallback: emit the raw SymbolID (legible-ish),
+                // and return without crashing.
+                result.append(toBase16(I.id));
+                return;
+            }
+        }
+
         auto& [unqualified, n_disambig, id_str] = it->second;
 
         // Append the unqualified name to the result

test-files/golden-tests/regression/1057.yml

@@ -0,0 +1 @@
+warn-if-undoc-enum-val: false