tdf#42949 Fix IWYU warnings in include/comphelper/[a-l]*

Found with bin/find-unneeded-includes
Only removal proposals are dealt with here.

Change-Id: I22ba2c8aec235e34cd7835b8a0a716bf3057db7a
Reviewed-on: https://gerrit.libreoffice.org/60837
Tested-by: Jenkins
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>

32 files changed, 95 insertions, 82 deletions

diff --git a/include/comphelper/ChainablePropertySet.hxx b/include/comphelper/ChainablePropertySet.hxx
index e048883ada7c..829b1a2d9fb6 100644
--- a/include/comphelper/ChainablePropertySet.hxx
+++ b/include/comphelper/ChainablePropertySet.hxx
@@ -24,12 +24,13 @@
 #include <com/sun/star/beans/XPropertyState.hpp>
 #include <com/sun/star/beans/XMultiPropertySet.hpp>
 #include <com/sun/star/lang/XServiceInfo.hpp>
-#include <comphelper/PropertyInfoHash.hxx>
 #include <comphelper/comphelperdllapi.h>
-#include <comphelper/solarmutex.hxx>
 #include <cppuhelper/implbase.hxx>
 #include <rtl/ref.hxx>
 
+namespace comphelper { class SolarMutex; }
+namespace comphelper { struct PropertyInfo; }
+
 namespace comphelper
 {
     class ChainablePropertySetInfo;
diff --git a/include/comphelper/IdPropArrayHelper.hxx b/include/comphelper/IdPropArrayHelper.hxx
index fdc0d4614d72..6a0f5b48975d 100644
--- a/include/comphelper/IdPropArrayHelper.hxx
+++ b/include/comphelper/IdPropArrayHelper.hxx
@@ -23,9 +23,7 @@
 
 #include <map>
 
-#include <cppuhelper/component.hxx>
 #include <osl/mutex.hxx>
-#include <cppuhelper/interfacecontainer.hxx>
 #include <osl/diagnose.h>
 #include <rtl/instance.hxx>
 #include <cppuhelper/propshlp.hxx>
diff --git a/include/comphelper/accessiblecontexthelper.hxx b/include/comphelper/accessiblecontexthelper.hxx
index c29f61ff3bb0..7af467872faa 100644
--- a/include/comphelper/accessiblecontexthelper.hxx
+++ b/include/comphelper/accessiblecontexthelper.hxx
@@ -24,7 +24,6 @@
 #include <cppuhelper/basemutex.hxx>
 #include <com/sun/star/accessibility/XAccessibleContext.hpp>
 #include <com/sun/star/accessibility/XAccessibleEventBroadcaster.hpp>
-#include <com/sun/star/lang/DisposedException.hpp>
 #include <comphelper/comphelperdllapi.h>
 #include <comphelper/solarmutex.hxx>
 #include <memory>
diff --git a/include/comphelper/accessibleeventnotifier.hxx b/include/comphelper/accessibleeventnotifier.hxx
index f8cf110f65ad..90df00caabb4 100644
--- a/include/comphelper/accessibleeventnotifier.hxx
+++ b/include/comphelper/accessibleeventnotifier.hxx
@@ -20,11 +20,13 @@
 #ifndef INCLUDED_COMPHELPER_ACCESSIBLEEVENTNOTIFIER_HXX
 #define INCLUDED_COMPHELPER_ACCESSIBLEEVENTNOTIFIER_HXX
 
-#include <com/sun/star/accessibility/AccessibleEventObject.hpp>
-#include <com/sun/star/accessibility/XAccessibleEventListener.hpp>
-
 #include <comphelper/comphelperdllapi.h>
 
+namespace com { namespace sun { namespace star { namespace uno { class XInterface; } } } }
+namespace com { namespace sun { namespace star { namespace uno { template <class interface_type> class Reference; } } } }
+namespace com { namespace sun { namespace star { namespace accessibility { class XAccessibleEventListener; } } } }
+namespace com { namespace sun { namespace star { namespace accessibility { struct AccessibleEventObject; } } } }
+
 namespace comphelper {
 
 class COMPHELPER_DLLPUBLIC AccessibleEventNotifier
diff --git a/include/comphelper/accessibletexthelper.hxx b/include/comphelper/accessibletexthelper.hxx
index 4f400f5d79e4..04de7c7d87e9 100644
--- a/include/comphelper/accessibletexthelper.hxx
+++ b/include/comphelper/accessibletexthelper.hxx
@@ -22,12 +22,13 @@
 
 #include <com/sun/star/accessibility/XAccessibleText.hpp>
 #include <com/sun/star/accessibility/TextSegment.hpp>
-#include <com/sun/star/i18n/XBreakIterator.hpp>
-#include <com/sun/star/i18n/XCharacterClassification.hpp>
 #include <comphelper/accessiblecomponenthelper.hxx>
 #include <cppuhelper/implbase1.hxx>
 #include <comphelper/comphelperdllapi.h>
 
+namespace com { namespace sun { namespace star { namespace i18n { class XBreakIterator; } } } }
+namespace com { namespace sun { namespace star { namespace i18n { class XCharacterClassification; } } } }
+namespace com { namespace sun { namespace star { namespace i18n { struct Boundary; } } } }
 
 namespace comphelper
 {
diff --git a/include/comphelper/accessiblewrapper.hxx b/include/comphelper/accessiblewrapper.hxx
index 73643169cd39..30f775f255e5 100644
--- a/include/comphelper/accessiblewrapper.hxx
+++ b/include/comphelper/accessiblewrapper.hxx
@@ -30,17 +30,17 @@
 #include <com/sun/star/accessibility/XAccessibleEventBroadcaster.hpp>
 #include <com/sun/star/accessibility/XAccessibleEventListener.hpp>
 #include <cppuhelper/compbase.hxx>
-#include <com/sun/star/lang/XComponent.hpp>
 #include <cppuhelper/implbase.hxx>
 #include <cppuhelper/implbase1.hxx>
 #include <cppuhelper/basemutex.hxx>
 #include <comphelper/uno3.hxx>
-#include <cppuhelper/interfacecontainer.hxx>
+#include <cppuhelper/interfacecontainer.h>
 #include <comphelper/accessibleeventnotifier.hxx>
 #include <comphelper/stl_types.hxx>
 #include <comphelper/comphelperdllapi.h>
 #include <rtl/ref.hxx>
 
+namespace com { namespace sun { namespace star { namespace uno { class XComponentContext; } } } }
 
 namespace comphelper
 {
diff --git a/include/comphelper/accimplaccess.hxx b/include/comphelper/accimplaccess.hxx
index a304ccc3cc94..86b16c8ad97a 100644
--- a/include/comphelper/accimplaccess.hxx
+++ b/include/comphelper/accimplaccess.hxx
@@ -23,12 +23,6 @@
 #include <cppuhelper/implbase1.hxx>
 #include <com/sun/star/lang/XUnoTunnel.hpp>
 #include <comphelper/comphelperdllapi.h>
-#include <memory>
-
-namespace com { namespace sun { namespace star { namespace accessibility {
-    class XAccessible;
-    class XAccessibleContext;
-}}}}
 
 namespace comphelper
 {
diff --git a/include/comphelper/backupfilehelper.hxx b/include/comphelper/backupfilehelper.hxx
index 2ad1e54ae0a3..33042e917ec3 100644
--- a/include/comphelper/backupfilehelper.hxx
+++ b/include/comphelper/backupfilehelper.hxx
@@ -14,9 +14,6 @@
 
 #include <comphelper/comphelperdllapi.h>
 #include <rtl/ustring.hxx>
-#include <sal/log.hxx>
-#include <osl/file.hxx>
-#include <memory>
 #include <set>
 #include <vector>
 
diff --git a/include/comphelper/base64.hxx b/include/comphelper/base64.hxx
index cfa80bf39a25..763312caaa78 100644
--- a/include/comphelper/base64.hxx
+++ b/include/comphelper/base64.hxx
@@ -25,7 +25,8 @@
 #include <sal/types.h>
 #include <rtl/ustrbuf.hxx>
 #include <rtl/strbuf.hxx>
-#include <com/sun/star/uno/Sequence.h>
+
+namespace com { namespace sun { namespace star { namespace uno { template <class E> class Sequence; } } } }
 
 namespace comphelper {
 
diff --git a/include/comphelper/basicio.hxx b/include/comphelper/basicio.hxx
index de444e0c12a1..cd54f37a569b 100644
--- a/include/comphelper/basicio.hxx
+++ b/include/comphelper/basicio.hxx
@@ -20,10 +20,11 @@
 #ifndef INCLUDED_COMPHELPER_BASICIO_HXX
 #define INCLUDED_COMPHELPER_BASICIO_HXX
 
-#include <com/sun/star/io/XPersistObject.hpp>
-#include <com/sun/star/awt/FontDescriptor.hpp>
+#include <com/sun/star/io/XObjectOutputStream.hpp>
+#include <com/sun/star/io/XObjectInputStream.hpp>
 #include <comphelper/comphelperdllapi.h>
 
+namespace com { namespace sun { namespace star { namespace awt { struct FontDescriptor; } } } }
 
 namespace comphelper
 {
diff --git a/include/comphelper/componentbase.hxx b/include/comphelper/componentbase.hxx
index 993b81eeeb73..3d785087b87a 100644
--- a/include/comphelper/componentbase.hxx
+++ b/include/comphelper/componentbase.hxx
@@ -21,7 +21,7 @@
 #define INCLUDED_COMPHELPER_COMPONENTBASE_HXX
 
 #include <comphelper/comphelperdllapi.h>
-#include <cppuhelper/interfacecontainer.hxx>
+#include <cppuhelper/interfacecontainer.h>
 
 
 namespace comphelper
diff --git a/include/comphelper/componentguard.hxx b/include/comphelper/componentguard.hxx
index 072b2857dabd..f3cf1bd5e426 100644
--- a/include/comphelper/componentguard.hxx
+++ b/include/comphelper/componentguard.hxx
@@ -23,7 +23,7 @@
 #include <com/sun/star/lang/DisposedException.hpp>
 
 #include <cppuhelper/weak.hxx>
-#include <cppuhelper/interfacecontainer.hxx>
+#include <cppuhelper/interfacecontainer.h>
 
 
 namespace comphelper
diff --git a/include/comphelper/componentmodule.hxx b/include/comphelper/componentmodule.hxx
index 67818ac3d8a3..a60c83aee70d 100644
--- a/include/comphelper/componentmodule.hxx
+++ b/include/comphelper/componentmodule.hxx
@@ -28,8 +28,6 @@
 
 #include <osl/mutex.hxx>
 
-#include <rtl/string.hxx>
-#include <rtl/instance.hxx>
 #include <memory>
 
 
diff --git a/include/comphelper/configuration.hxx b/include/comphelper/configuration.hxx
index d2df43b4d880..fa298c54a621 100644
--- a/include/comphelper/configuration.hxx
+++ b/include/comphelper/configuration.hxx
@@ -14,7 +14,7 @@
 
 #include <boost/optional.hpp>
 #include <com/sun/star/uno/Any.hxx>
-#include <com/sun/star/uno/Reference.hxx>
+#include <com/sun/star/uno/Reference.h>
 #include <comphelper/comphelperdllapi.h>
 #include <comphelper/processfactory.hxx>
 #include <sal/types.h>
diff --git a/include/comphelper/configurationhelper.hxx b/include/comphelper/configurationhelper.hxx
index 48b1e240f104..eb9e7b8fd3f5 100644
--- a/include/comphelper/configurationhelper.hxx
+++ b/include/comphelper/configurationhelper.hxx
@@ -20,17 +20,14 @@
 #ifndef INCLUDED_COMPHELPER_CONFIGURATIONHELPER_HXX
 #define INCLUDED_COMPHELPER_CONFIGURATIONHELPER_HXX
 
-#include <com/sun/star/uno/XInterface.hpp>
-#include <com/sun/star/uno/XComponentContext.hpp>
-#include <com/sun/star/lang/XMultiServiceFactory.hpp>
-#include <com/sun/star/beans/PropertyValue.hpp>
-#include <com/sun/star/container/XHierarchicalNameAccess.hpp>
-#include <com/sun/star/util/XChangesBatch.hpp>
+#include <com/sun/star/uno/Reference.h>
+#include <com/sun/star/uno/Any.hxx>
 #include <rtl/ustring.hxx>
-#include <rtl/ustrbuf.hxx>
 #include <comphelper/comphelperdllapi.h>
 #include <o3tl/typed_flags_set.hxx>
 
+namespace com { namespace sun { namespace star { namespace uno { class XComponentContext; } } } }
+namespace com { namespace sun { namespace star { namespace uno { class XInterface; } } } }
 
 namespace comphelper
 {
diff --git a/include/comphelper/configurationlistener.hxx b/include/comphelper/configurationlistener.hxx
index 7dc39a308144..4897323b8b9e 100644
--- a/include/comphelper/configurationlistener.hxx
+++ b/include/comphelper/configurationlistener.hxx
@@ -10,19 +10,18 @@
 #ifndef INCLUDED_COMPHELPER_CONFIGURATIONLISTENER_HXX
 #define INCLUDED_COMPHELPER_CONFIGURATIONLISTENER_HXX
 
-#include <algorithm>
 #include <vector>
-#include <iterator>
 #include <comphelper/comphelperdllapi.h>
-#include <com/sun/star/lang/XComponent.hpp>
 #include <com/sun/star/beans/XPropertySet.hpp>
-#include <com/sun/star/beans/PropertyChangeEvent.hpp>
 #include <com/sun/star/beans/XPropertyChangeListener.hpp>
 #include <rtl/ref.hxx>
 #include <cppuhelper/implbase.hxx>
 #include <comphelper/processfactory.hxx>
 #include <comphelper/configurationhelper.hxx>
 
+namespace com { namespace sun { namespace star { namespace beans { struct PropertyChangeEvent; } } } }
+namespace com { namespace sun { namespace star { namespace uno { class XComponentContext; } } } }
+
 namespace comphelper {
 
 class ConfigurationListener;
diff --git a/include/comphelper/dispatchcommand.hxx b/include/comphelper/dispatchcommand.hxx
index 0a8e158366bd..475317742157 100644
--- a/include/comphelper/dispatchcommand.hxx
+++ b/include/comphelper/dispatchcommand.hxx
@@ -12,9 +12,11 @@
 
 #include <comphelper/comphelperdllapi.h>
 #include <rtl/ustring.hxx>
-#include <com/sun/star/uno/Sequence.hxx>
-#include <com/sun/star/beans/PropertyValue.hpp>
-#include <com/sun/star/frame/XDispatchResultListener.hpp>
+#include <com/sun/star/uno/Reference.hxx>
+
+namespace com { namespace sun { namespace star { namespace beans { struct PropertyValue; } } } }
+namespace com { namespace sun { namespace star { namespace frame { class XDispatchResultListener; } } } }
+namespace com { namespace sun { namespace star { namespace uno { template <typename > class Sequence; } } } }
 
 namespace comphelper
 {
diff --git a/include/comphelper/docpasswordhelper.hxx b/include/comphelper/docpasswordhelper.hxx
index 62c856c40c9a..240545848b30 100644
--- a/include/comphelper/docpasswordhelper.hxx
+++ b/include/comphelper/docpasswordhelper.hxx
@@ -20,7 +20,6 @@
 #ifndef INCLUDED_COMPHELPER_DOCPASSWORDHELPER_HXX
 #define INCLUDED_COMPHELPER_DOCPASSWORDHELPER_HXX
 
-#include <com/sun/star/beans/NamedValue.hpp>
 #include <comphelper/comphelperdllapi.h>
 #include <vector>
 #include <comphelper/docpasswordrequest.hxx>
@@ -28,6 +27,7 @@
 
 namespace com { namespace sun { namespace star { namespace task { class XInteractionHandler; } } } }
 namespace com { namespace sun { namespace star { namespace beans { struct PropertyValue; } } } }
+namespace com { namespace sun { namespace star { namespace beans { struct NamedValue; } } } }
 
 namespace comphelper {
 
diff --git a/include/comphelper/docpasswordrequest.hxx b/include/comphelper/docpasswordrequest.hxx
index 5440616f849d..31b49bb09c72 100644
--- a/include/comphelper/docpasswordrequest.hxx
+++ b/include/comphelper/docpasswordrequest.hxx
@@ -22,11 +22,12 @@
 
 #include <comphelper/comphelperdllapi.h>
 #include <com/sun/star/task/PasswordRequestMode.hpp>
-#include <com/sun/star/task/XInteractionAbort.hpp>
 #include <com/sun/star/task/XInteractionRequest.hpp>
 #include <cppuhelper/implbase.hxx>
 #include <rtl/ref.hxx>
 
+namespace com { namespace sun { namespace star { namespace task { class XInteractionAbort; } } } }
+
 namespace comphelper {
 
 class PasswordContinuation;
diff --git a/include/comphelper/documentconstants.hxx b/include/comphelper/documentconstants.hxx
index 89d5178d33d5..3f7f166416e0 100644
--- a/include/comphelper/documentconstants.hxx
+++ b/include/comphelper/documentconstants.hxx
@@ -19,7 +19,6 @@
 #ifndef INCLUDED_COMPHELPER_DOCUMENTCONSTANTS_HXX
 #define INCLUDED_COMPHELPER_DOCUMENTCONSTANTS_HXX
 
-#include <rtl/ustring.hxx>
 #include <o3tl/typed_flags_set.hxx>
 
 // formats of SO6/7
diff --git a/include/comphelper/documentinfo.hxx b/include/comphelper/documentinfo.hxx
index c30d79b40c95..d47f1d02ea50 100644
--- a/include/comphelper/documentinfo.hxx
+++ b/include/comphelper/documentinfo.hxx
@@ -21,8 +21,10 @@
 #define INCLUDED_COMPHELPER_DOCUMENTINFO_HXX
 
 #include <comphelper/comphelperdllapi.h>
+#include <rtl/ustring.hxx>
 
-#include <com/sun/star/frame/XModel.hpp>
+namespace com { namespace sun { namespace star { namespace frame { class XModel; } } } }
+namespace com { namespace sun { namespace star { namespace uno { template <class interface_type> class Reference; } } } }
 
 
 namespace comphelper {
diff --git a/include/comphelper/embeddedobjectcontainer.hxx b/include/comphelper/embeddedobjectcontainer.hxx
index 466cb49ebede..93f7327b5435 100644
--- a/include/comphelper/embeddedobjectcontainer.hxx
+++ b/include/comphelper/embeddedobjectcontainer.hxx
@@ -20,17 +20,19 @@
 #define INCLUDED_COMPHELPER_EMBEDDEDOBJECTCONTAINER_HXX
 
 #include <com/sun/star/uno/Reference.h>
-#include <com/sun/star/uno/Sequence.hxx>
-#include <com/sun/star/embed/XEmbeddedObject.hpp>
-#include <com/sun/star/task/XInteractionHandler.hpp>
-#include <com/sun/star/embed/XStorage.hpp>
-#include <com/sun/star/io/XInputStream.hpp>
-#include <com/sun/star/beans/PropertyValue.hpp>
+#include <com/sun/star/uno/Sequence.h>
 #include <comphelper/comphelperdllapi.h>
 
 #include <rtl/ustring.hxx>
 #include <memory>
 
+namespace com { namespace sun { namespace star { namespace beans { struct PropertyValue; } } } }
+namespace com { namespace sun { namespace star { namespace embed { class XEmbeddedObject; } } } }
+namespace com { namespace sun { namespace star { namespace embed { class XStorage; } } } }
+namespace com { namespace sun { namespace star { namespace io { class XInputStream; } } } }
+namespace com { namespace sun { namespace star { namespace task { class XInteractionHandler; } } } }
+namespace com { namespace sun { namespace star { namespace uno { class XInterface; } } } }
+
 namespace comphelper
 {
     class EmbeddedObjectContainer;
diff --git a/include/comphelper/eventattachermgr.hxx b/include/comphelper/eventattachermgr.hxx
index 97e6dee6c1d5..22323514aace 100644
--- a/include/comphelper/eventattachermgr.hxx
+++ b/include/comphelper/eventattachermgr.hxx
@@ -20,20 +20,16 @@
 #ifndef INCLUDED_COMPHELPER_EVENTATTACHERMGR_HXX
 #define INCLUDED_COMPHELPER_EVENTATTACHERMGR_HXX
 
-#include <com/sun/star/uno/Reference.hxx>
+#include <com/sun/star/uno/Reference.h>
 #include <comphelper/comphelperdllapi.h>
 
 namespace com { namespace sun { namespace star {
 namespace uno {
-    class Exception;
     class XComponentContext;
 }
 namespace script {
     class XEventAttacherManager;
 }
-namespace beans {
-    class XIntrospection;
-}
 } } }
 
 
diff --git a/include/comphelper/extract.hxx b/include/comphelper/extract.hxx
index e0eab28897af..91682400d770 100644
--- a/include/comphelper/extract.hxx
+++ b/include/comphelper/extract.hxx
@@ -25,9 +25,8 @@
 
 #include <com/sun/star/lang/IllegalArgumentException.hpp>
 #include <com/sun/star/uno/TypeClass.hpp>
-#include <com/sun/star/uno/Type.hxx>
+#include <com/sun/star/uno/Type.h>
 #include <com/sun/star/uno/Any.hxx>
-#include <cppu/unotype.hxx>
 
 namespace cppu
 {
diff --git a/include/comphelper/genericpropertyset.hxx b/include/comphelper/genericpropertyset.hxx
index ca30d46a2cdb..527b7d8e4960 100644
--- a/include/comphelper/genericpropertyset.hxx
+++ b/include/comphelper/genericpropertyset.hxx
@@ -20,10 +20,12 @@
 #ifndef INCLUDED_COMPHELPER_GENERICPROPERTYSET_HXX
 #define INCLUDED_COMPHELPER_GENERICPROPERTYSET_HXX
 
-#include <comphelper/propertysetinfo.hxx>
-#include <com/sun/star/beans/XPropertySet.hpp>
+#include <com/sun/star/uno/Reference.h>
 #include <comphelper/comphelperdllapi.h>
 
+namespace com { namespace sun { namespace star { namespace beans { class XPropertySet; } } } }
+namespace comphelper { class PropertySetInfo; }
+
 namespace comphelper
 {
     COMPHELPER_DLLPUBLIC css::uno::Reference< css::beans::XPropertySet > GenericPropertySet_CreateInstance( PropertySetInfo* pInfo );
diff --git a/include/comphelper/getexpandeduri.hxx b/include/comphelper/getexpandeduri.hxx
index 9da095821e66..ab73a5ff8596 100644
--- a/include/comphelper/getexpandeduri.hxx
+++ b/include/comphelper/getexpandeduri.hxx
@@ -12,15 +12,15 @@
 
 #include <sal/config.h>
 
-#include <com/sun/star/uno/Reference.hxx>
 #include <comphelper/comphelperdllapi.h>
 #include <rtl/ustring.hxx>
-#include <sal/types.h>
 
 namespace com { namespace sun { namespace star { namespace uno {
     class XComponentContext;
 } } } }
 
+namespace com { namespace sun { namespace star { namespace uno { template <typename > class Reference; } } } }
+
 namespace comphelper {
 
 /**
diff --git a/include/comphelper/graphicmimetype.hxx b/include/comphelper/graphicmimetype.hxx
index 7cf1e88240c0..c278ee669d03 100644
--- a/include/comphelper/graphicmimetype.hxx
+++ b/include/comphelper/graphicmimetype.hxx
@@ -14,9 +14,34 @@
 #include <rtl/ustring.hxx>
 #include <vcl/salctype.hxx>
 
-#include <com/sun/star/graphic/XGraphic.hpp>
-#include <com/sun/star/io/XInputStream.hpp>
-#include <com/sun/star/uno/Reference.hxx>
+#include <com/sun/star/uno/Reference.h>
+
+namespace com
+{
+namespace sun
+{
+namespace star
+{
+namespace graphic
+{
+class XGraphic;
+}
+}
+}
+}
+namespace com
+{
+namespace sun
+{
+namespace star
+{
+namespace io
+{
+class XInputStream;
+}
+}
+}
+}
 
 namespace comphelper
 {
diff --git a/include/comphelper/guarding.hxx b/include/comphelper/guarding.hxx
index a750d479064b..3bbf4ac71390 100644
--- a/include/comphelper/guarding.hxx
+++ b/include/comphelper/guarding.hxx
@@ -20,7 +20,7 @@
 #ifndef INCLUDED_COMPHELPER_GUARDING_HXX
 #define INCLUDED_COMPHELPER_GUARDING_HXX
 
-#include <osl/mutex.hxx>
+namespace osl { class Mutex; }
 
 
 namespace comphelper
diff --git a/include/comphelper/interfacecontainer2.hxx b/include/comphelper/interfacecontainer2.hxx
index 22c1277e5fe0..f5907d205aa7 100644
--- a/include/comphelper/interfacecontainer2.hxx
+++ b/include/comphelper/interfacecontainer2.hxx
@@ -21,21 +21,16 @@
 
 #include <sal/config.h>
 
-#include <cstddef>
-#include <functional>
 #include <vector>
-#include <utility>
 
-#include <osl/diagnose.h>
-#include <osl/mutex.hxx>
-#include <rtl/alloc.h>
-#include <com/sun/star/uno/Sequence.hxx>
-#include <com/sun/star/uno/XInterface.hpp>
 #include <com/sun/star/lang/EventObject.hpp>
 
 #include <com/sun/star/lang/DisposedException.hpp>
 #include <comphelper/comphelperdllapi.h>
 
+namespace com { namespace sun { namespace star { namespace uno { class XInterface; } } } }
+namespace osl { class Mutex; }
+
 /** */ //for docpp
 namespace comphelper
 {
diff --git a/include/comphelper/listenernotification.hxx b/include/comphelper/listenernotification.hxx
index 610ac31cb6ce..cadb85297d8f 100644
--- a/include/comphelper/listenernotification.hxx
+++ b/include/comphelper/listenernotification.hxx
@@ -22,11 +22,12 @@
 
 #include <comphelper/interfacecontainer2.hxx>
 
-#include <com/sun/star/lang/XEventListener.hpp>
+#include <com/sun/star/lang/EventObject.hpp>
 #include <comphelper/comphelperdllapi.h>
 
 #include <memory>
 
+namespace com { namespace sun { namespace star { namespace lang { class XEventListener; } } } }
 
 namespace comphelper
 {
diff --git a/include/comphelper/logging.hxx b/include/comphelper/logging.hxx
index fd04e83f732d..475f067062bf 100644
--- a/include/comphelper/logging.hxx
+++ b/include/comphelper/logging.hxx
@@ -21,14 +21,14 @@
 #define INCLUDED_COMPHELPER_LOGGING_HXX
 
 #include <comphelper/comphelperdllapi.h>
-
-#include <com/sun/star/uno/XComponentContext.hpp>
-#include <com/sun/star/logging/XLogHandler.hpp>
-#include <com/sun/star/logging/LogLevel.hpp>
+#include <rtl/ustring.hxx>
 
 #include <boost/optional.hpp>
 #include <memory>
 
+namespace com { namespace sun { namespace star { namespace uno { template <class interface_type> class Reference; } } } }
+namespace com { namespace sun { namespace star { namespace uno { class XComponentContext; } } } }
+
 namespace comphelper
 {
 
diff --git a/include/comphelper/lok.hxx b/include/comphelper/lok.hxx
index e0bd65690261..7fb4d5a04800 100644
--- a/include/comphelper/lok.hxx
+++ b/include/comphelper/lok.hxx
@@ -11,8 +11,9 @@
 #define INCLUDED_COMPHELPER_LOK_HXX
 
 #include <comphelper/comphelperdllapi.h>
+#include <rtl/ustring.hxx>
 
-#include <i18nlangtag/languagetag.hxx>
+class LanguageTag;
 
 // Interface between the LibreOfficeKit implementation called by LibreOfficeKit clients and other
 // LibreOffice code.