Run IWYU

src/contrib/graphbuilder.cpp

@@ -1,8 +1,10 @@
-#include "yaml-cpp/parser.h"
-#include "yaml-cpp/contrib/graphbuilder.h"
 #include "graphbuilderadapter.h"
 
+#include "yaml-cpp/parser.h"  // IWYU pragma: keep
+
 namespace YAML {
+class GraphBuilderInterface;
+
 void* BuildGraphOfNextDocument(Parser& parser,
                                GraphBuilderInterface& graphBuilder) {
   GraphBuilderAdapter eventHandler(graphBuilder);

src/contrib/graphbuilderadapter.cpp

@@ -1,6 +1,9 @@
 #include "graphbuilderadapter.h"
+#include "yaml-cpp/contrib/graphbuilder.h"
 
 namespace YAML {
+struct Mark;
+
 int GraphBuilderAdapter::ContainerFrame::sequenceMarker;
 
 void GraphBuilderAdapter::OnNull(const Mark &mark, anchor_t anchor) {

src/contrib/graphbuilderadapter.h

@@ -10,9 +10,16 @@
 #include <cstdlib>
 #include <map>
 #include <stack>
-#include "yaml-cpp/eventhandler.h"
+
+#include "yaml-cpp/anchor.h"
 #include "yaml-cpp/contrib/anchordict.h"
 #include "yaml-cpp/contrib/graphbuilder.h"
+#include "yaml-cpp/eventhandler.h"
+
+namespace YAML {
+class GraphBuilderInterface;
+struct Mark;
+}  // namespace YAML
 
 namespace YAML {
 class GraphBuilderAdapter : public EventHandler {