Merge IWYU from core

src/scantoken.cpp

-#include "scanner.h"
-#include "token.h"
-#include "yaml-cpp/exceptions.h"
+#include <sstream>
+
 #include "exp.h"
+#include "regex_yaml.h"
+#include "regeximpl.h"
+#include "scanner.h"
 #include "scanscalar.h"
-#include "scantag.h"
-#include "tag.h"
-#include <sstream>
+#include "scantag.h"  // IWYU pragma: keep
+#include "tag.h"  // IWYU pragma: keep
+#include "token.h"
+#include "yaml-cpp/exceptions.h"  // IWYU pragma: keep
+#include "yaml-cpp/mark.h"
 
 namespace YAML {
 ///////////////////////////////////////////////////////////////////////

src/simplekey.cpp

 #include "scanner.h"
 #include "token.h"
-#include "yaml-cpp/exceptions.h"
-#include "exp.h"
 
 namespace YAML {
+struct Mark;
+
 Scanner::SimpleKey::SimpleKey(const Mark& mark_, int flowLevel_)
     : mark(mark_), flowLevel(flowLevel_), pIndent(0), pMapStart(0), pKey(0) {}
 

src/singledocparser.cpp

-#include "singledocparser.h"
-#include "collectionstack.h"
-#include "directives.h"
-#include "yaml-cpp/eventhandler.h"
-#include "yaml-cpp/exceptions.h"
+#include <algorithm>
+#include <cstdio>
+#include <sstream>
+
+#include "collectionstack.h"  // IWYU pragma: keep
 #include "scanner.h"
+#include "singledocparser.h"
 #include "tag.h"
 #include "token.h"
-#include <sstream>
-#include <cstdio>
-#include <algorithm>
+#include "yaml-cpp/eventhandler.h"
+#include "yaml-cpp/exceptions.h"  // IWYU pragma: keep
+#include "yaml-cpp/mark.h"
 
 namespace YAML {
 SingleDocParser::SingleDocParser(Scanner& scanner, const Directives& directives)

src/singledocparser.h

@@ -7,20 +7,21 @@
 #pragma once
 #endif
 
-#include "yaml-cpp/anchor.h"
-#include "yaml-cpp/noncopyable.h"
-#include <string>
 #include <map>
 #include <memory>
+#include <string>
+
+#include "yaml-cpp/anchor.h"
+#include "yaml-cpp/noncopyable.h"
 
 namespace YAML {
-struct Directives;
-struct Mark;
-struct Token;
 class CollectionStack;
 class EventHandler;
 class Node;
 class Scanner;
+struct Directives;
+struct Mark;
+struct Token;
 
 class SingleDocParser : private noncopyable {
  public:

src/stream.cpp

-#include "stream.h"
 #include <iostream>
-#include "exp.h"
+
+#include "stream.h"
 
 #ifndef YAML_PREFETCH_SIZE
 #define YAML_PREFETCH_SIZE 2048

src/tag.cpp

-#include "tag.h"
-#include "directives.h"
-#include "token.h"
 #include <cassert>
 #include <stdexcept>
 
+#include "directives.h"  // IWYU pragma: keep
+#include "tag.h"
+#include "token.h"
+
 namespace YAML {
 Tag::Tag(const Token& token) : type(static_cast<TYPE>(token.data)) {
   switch (type) {

src/tag.h

@@ -10,8 +10,8 @@
 #include <string>
 
 namespace YAML {
-struct Token;
 struct Directives;
+struct Token;
 
 struct Tag {
   enum TYPE {

test/core/parsertests.cpp

-#include "parsertests.h"
-#include "handlermacros.h"
-#include "yaml-cpp/yaml.h"
 #include <iostream>
 
+#include "handlermacros.h"
+#include "parsertests.h"  // IWYU pragma: keep
+#include "teststruct.h"
+#include "yaml-cpp/parser.h"
+
+namespace YAML {
+class Exception;
+class ParserException;
+}  // namespace YAML
+
 namespace Test {
 namespace Parser {
 TEST NoEndOfMapFlow() {

test/core/spectests.cpp

-#include "spectests.h"
-#include "handlermacros.h"
-#include "specexamples.h"
-#include "yaml-cpp/yaml.h"
 #include <cassert>
 
+#include "handlermacros.h"
+#include "specexamples.h"  // IWYU pragma: keep
+#include "spectests.h"  // IWYU pragma: keep
+#include "yaml-cpp/yaml.h"  // IWYU pragma: keep
+
 namespace Test {
 namespace Spec {
 // 2.1

test/emittertests.cpp

-#include "tests.h"
-#include "handlermacros.h"
-#include "yaml-cpp/yaml.h"
 #include <iostream>
 
+#include "teststruct.h"
+#include "yaml-cpp/eventhandler.h"
+#include "yaml-cpp/yaml.h"  // IWYU pragma: keep
+
 namespace Test {
 namespace Emitter {
 ////////////////////////////////////////////////////////////////////////////////////////////////////////

test/ostream_wrapper_test.cpp

-#include "yaml-cpp/ostream_wrapper.h"
-
+#include <stddef.h>
 #include <sstream>
 
 #include "gtest/gtest.h"
+#include "yaml-cpp/ostream_wrapper.h"
 
 namespace {
 TEST(OstreamWrapperTest, BufferNoWrite) {

test/spectests.cpp

-#include "spectests.h"
-#include "yaml-cpp/yaml.h"
 #include <iostream>
 
+#include "spectests.h"
+#include "yaml-cpp/yaml.h"  // IWYU pragma: keep
+
+namespace YAML {
+class Exception;
+}  // namespace YAML
+
 namespace Test {
 namespace {
 void RunSpecTest(TEST (*test)(), const std::string& index,

test/tests.cpp

-#include "tests.h"
+#include <fstream>
+#include <iostream>
+#include <sstream>
+#include <vector>
+
 #include "emittertests.h"
 #include "nodetests.h"
 #include "parsertests.h"
 #include "spectests.h"
-#include "yaml-cpp/yaml.h"
-#include <fstream>
-#include <sstream>
-#include <vector>
-#include <iostream>
+#include "tests.h"
 
 namespace Test {
 void RunAll() {

util/read.cpp

-#include "yaml-cpp/yaml.h"
-#include "yaml-cpp/eventhandler.h"
 #include <iostream>
 
+#include "yaml-cpp/yaml.h"  // IWYU pragma: keep
+
 class NullEventHandler : public YAML::EventHandler {
  public:
   typedef YAML::Mark Mark;

util/sandbox.cpp

-#include "yaml-cpp/yaml.h"
-#include "yaml-cpp/eventhandler.h"
 #include <iostream>
 
+#include "yaml-cpp/eventhandler.h"
+#include "yaml-cpp/yaml.h"  // IWYU pragma: keep
+
 class NullEventHandler : public YAML::EventHandler {
  public:
   typedef YAML::Mark Mark;