loplugin:bufferadd loosen some constraints

and extend O*StringView to have a constructor that takes a pointer and a
length

Change-Id: I6120e96280f030757e855a6596efdae438b7e1e8
Reviewed-on: https://gerrit.libreoffice.org/80872
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

54 files changed, 269 insertions, 403 deletions

diff --git a/bridges/source/jni_uno/jni_data.cxx b/bridges/source/jni_uno/jni_data.cxx
index feb9674563c5..daff48a48492 100644
--- a/bridges/source/jni_uno/jni_data.cxx
+++ b/bridges/source/jni_uno/jni_data.cxx
@@ -1786,11 +1786,7 @@ void Bridge::map_to_java(
         if (in_param)
         {
             // call static <enum_class>.fromInt( int )
-            OStringBuffer sig_buf( 5 + class_name.getLength() );
-            sig_buf.append( "(I)L" );
-            sig_buf.append( class_name.replace( '.', '/' ) );
-            sig_buf.append( ';' );
-            OString sig( sig_buf.makeStringAndClear() );
+            OString sig = "(I)L" + class_name.replace( '.', '/' ) + ";";
             jmethodID method_id = jni->GetStaticMethodID(
                 static_cast<jclass>(jo_enum_class.get()), "fromInt", sig.getStr() );
             jni.ensure_no_exception();
@@ -2275,11 +2271,7 @@ void Bridge::map_to_java(
             if (0 < nElements)
             {
                 // call static <enum_class>.fromInt( int )
-                OStringBuffer sig_buf( 5 + class_name.getLength() );
-                sig_buf.append( "(I)L" );
-                sig_buf.append( class_name.replace( '.', '/' ) );
-                sig_buf.append( ';' );
-                OString sig( sig_buf.makeStringAndClear() );
+                OString sig = "(I)L" + class_name.replace( '.', '/' ) + ";";
                 jmethodID method_id = jni->GetStaticMethodID(
                     static_cast<jclass>(jo_enum_class.get()), "fromInt", sig.getStr() );
                 jni.ensure_no_exception();
diff --git a/compilerplugins/clang/bufferadd.cxx b/compilerplugins/clang/bufferadd.cxx
index deb97bb35c11..a1c9738f0041 100644
--- a/compilerplugins/clang/bufferadd.cxx
+++ b/compilerplugins/clang/bufferadd.cxx
@@ -51,6 +51,8 @@ public:
             return false;
         if (loplugin::isSamePathname(fn, SRCDIR "/writerfilter/source/dmapper/GraphicImport.cxx"))
             return false;
+        if (loplugin::isSamePathname(fn, SRCDIR "/sdext/source/pdfimport/pdfparse/pdfparse.cxx"))
+            return false;
         return true;
     }
 
@@ -174,14 +176,15 @@ void BufferAdd::findBufferAssignOrAdd(const Stmt* parentStmt, Stmt const* stmt)
                         return;
                     }
                     auto tc2 = loplugin::TypeCheck(cxxConstructExpr->getArg(0)->getType());
-                    if (cxxConstructExpr->getArg(0)->getType()->isBuiltinType()
-                        || tc2.LvalueReference().Class("OUStringBuffer")
+                    if (tc2.LvalueReference().Class("OUStringBuffer")
                         || tc2.LvalueReference().Class("OStringBuffer")
                         || tc2.Class("OUStringBuffer") || tc2.Class("OStringBuffer"))
                     {
                         badMap.insert(varDeclLHS);
                         return;
                     }
+                    addToGoodMap(varDeclLHS, parentStmt);
+                    return;
                 }
                 if (!isSideEffectFree(varDeclLHS->getInit()))
                     badMap.insert(varDeclLHS);
@@ -289,32 +292,6 @@ bool BufferAdd::isMethodOkToMerge(CXXMemberCallExpr const* memberCall)
         return false;
 
     auto rhs = memberCall->getArg(0);
-
-    if (loplugin::TypeCheck(memberCall->getType())
-            .Class("OStringBuffer")
-            .Namespace("rtl")
-            .GlobalNamespace())
-    {
-        // because we have no OStringLiteral1
-        if (tc2.Char())
-            return false;
-        // Can't see how to make the call to append(sal_Unicode*pStart, sal_Unicode*pEnd) work
-        if (memberCall->getNumArgs() == 2 && loplugin::TypeCheck(rhs->getType()).Pointer())
-            return false;
-    }
-    if (loplugin::TypeCheck(memberCall->getType())
-            .Class("OUStringBuffer")
-            .Namespace("rtl")
-            .GlobalNamespace())
-    {
-        // character literals we do with OUStringBuffer, not variables of type sal_Unicode/char
-        if (tc2.Typedef("sal_Unicode").GlobalNamespace() && !isa<CharacterLiteral>(rhs))
-            return false;
-        // Can't see how to make the call to append(sal_Unicode*pStart, sal_Unicode*pEnd) work
-        if (memberCall->getNumArgs() == 2
-            && loplugin::TypeCheck(memberCall->getArg(0)->getType()).Pointer())
-            return false;
-    }
     if (!isSideEffectFree(rhs))
         return false;
     return true;
@@ -357,7 +334,8 @@ bool BufferAdd::isSideEffectFree(Expr const* expr)
             if (calleeMethodDecl && calleeMethodDecl->getIdentifier())
             {
                 auto name = calleeMethodDecl->getName();
-                if (name == "number" || name == "unacquired")
+                if (callExpr->getNumArgs() > 0
+                    && (name == "number" || name == "unacquired" || name == "boolean"))
                 {
                     auto tc = loplugin::TypeCheck(calleeMethodDecl->getParent());
                     if (tc.Class("OUString") || tc.Class("OString"))
diff --git a/compilerplugins/clang/test/bufferadd.cxx b/compilerplugins/clang/test/bufferadd.cxx
index 1b08dcacb1bf..7d8d9a693b9f 100644
--- a/compilerplugins/clang/test/bufferadd.cxx
+++ b/compilerplugins/clang/test/bufferadd.cxx
@@ -29,6 +29,23 @@ void f2()
     OUStringBuffer v;
     v.append("xxx").append("aaaa");
 }
+void f3(OString class_name)
+{
+    // expected-error@+1 {{convert this append sequence into a *String + sequence [loplugin:bufferadd]}}
+    OStringBuffer sig_buf(5 + class_name.getLength());
+    sig_buf.append("(I)L");
+    //sig_buf.append( class_name.replace( '.', '/' ) );
+    sig_buf.append(';');
+    OString sig(sig_buf.makeStringAndClear());
+    (void)sig;
+}
+void f4(sal_Unicode const* pPathBegin)
+{
+    // expected-error@+1 {{convert this append sequence into a *String + sequence [loplugin:bufferadd]}}
+    OUStringBuffer v;
+    v.append(pPathBegin, 12);
+    v.append("aaaa");
+}
 }
 
 namespace test2
diff --git a/cui/source/customize/CustomNotebookbarGenerator.cxx b/cui/source/customize/CustomNotebookbarGenerator.cxx
index a839667e7449..f19e4c9f3c06 100644
--- a/cui/source/customize/CustomNotebookbarGenerator.cxx
+++ b/cui/source/customize/CustomNotebookbarGenerator.cxx
@@ -260,9 +260,9 @@ void CustomNotebookbarGenerator::createCustomizedUIFile()
 
 Sequence<OUString> CustomNotebookbarGenerator::getCustomizedUIItem(OUString sNotebookbarConfigType)
 {
-    OUStringBuffer aPath = getAppNameRegistryPath();
-    const utl::OConfigurationTreeRoot aAppNode(::comphelper::getProcessComponentContext(),
-                                               aPath.makeStringAndClear(), false);
+    OUString aPath = getAppNameRegistryPath();
+    const utl::OConfigurationTreeRoot aAppNode(::comphelper::getProcessComponentContext(), aPath,
+                                               false);
 
     const utl::OConfigurationNode aModesNode = aAppNode.openNode("Modes");
     const utl::OConfigurationNode aModeNode(aModesNode.openNode(sNotebookbarConfigType));
@@ -275,9 +275,9 @@ Sequence<OUString> CustomNotebookbarGenerator::getCustomizedUIItem(OUString sNot
 void CustomNotebookbarGenerator::setCustomizedUIItem(Sequence<OUString> sUIItemProperties,
                                                      OUString sNotebookbarConfigType)
 {
-    OUStringBuffer aPath = getAppNameRegistryPath();
-    const utl::OConfigurationTreeRoot aAppNode(::comphelper::getProcessComponentContext(),
-                                               aPath.makeStringAndClear(), true);
+    OUString aPath = getAppNameRegistryPath();
+    const utl::OConfigurationTreeRoot aAppNode(::comphelper::getProcessComponentContext(), aPath,
+                                               true);
     const utl::OConfigurationNode aModesNode = aAppNode.openNode("Modes");
     const utl::OConfigurationNode aModeNode(aModesNode.openNode(sNotebookbarConfigType));
 
diff --git a/dbaccess/source/ui/app/AppControllerDnD.cxx b/dbaccess/source/ui/app/AppControllerDnD.cxx
index 8e285146644c..ae1d4725c205 100644
--- a/dbaccess/source/ui/app/AppControllerDnD.cxx
+++ b/dbaccess/source/ui/app/AppControllerDnD.cxx
@@ -241,10 +241,9 @@ void OApplicationController::deleteObjects( ElementType _eType, const std::vecto
                     // which may also be a part of the list
                     // #i33353#
                     OSL_ENSURE( aThisRound->getLength() - 1 >= 0, "OApplicationController::deleteObjects: empty name?" );
-                    OUStringBuffer sSmallestSiblingName( *aThisRound );
-                    sSmallestSiblingName.append( sal_Unicode( '/' + 1) );
+                    OUString sSmallestSiblingName = *aThisRound + OUStringLiteral1( sal_Unicode( '/' + 1) );
 
-                    std::set< OUString >::const_iterator aUpperChildrenBound = aDeleteNames.lower_bound( sSmallestSiblingName.makeStringAndClear() );
+                    std::set< OUString >::const_iterator aUpperChildrenBound = aDeleteNames.lower_bound( sSmallestSiblingName );
                     for ( std::set< OUString >::const_iterator aObsolete = aThisRound;
                           aObsolete != aUpperChildrenBound;
                         )
diff --git a/desktop/source/deployment/manager/dp_activepackages.cxx b/desktop/source/deployment/manager/dp_activepackages.cxx
index f520e3301ea0..ab2cbf0d4a9f 100644
--- a/desktop/source/deployment/manager/dp_activepackages.cxx
+++ b/desktop/source/deployment/manager/dp_activepackages.cxx
@@ -47,18 +47,14 @@
 
 namespace {
 
-static char const separator = static_cast< char >(
-    static_cast< unsigned char >(0xFF));
+constexpr const char separator[] = "\xff";
 
 OString oldKey(OUString const & fileName) {
     return OUStringToOString(fileName, RTL_TEXTENCODING_UTF8);
 }
 
 OString newKey(OUString const & id) {
-    OStringBuffer b;
-    b.append(separator);
-    b.append(OUStringToOString(id, RTL_TEXTENCODING_UTF8));
-    return b.makeStringAndClear();
+    return separator + OUStringToOString(id, RTL_TEXTENCODING_UTF8);
 }
 
 ::dp_manager::ActivePackages::Data decodeOldData(
@@ -168,7 +164,7 @@ ActivePackages::Entries ActivePackages::getEntries() const {
     ::dp_misc::t_string2string_map m(m_map.getEntries());
     for (auto const& elem : m)
     {
-        if (!elem.first.isEmpty() && elem.first[0] == separator) {
+        if (!elem.first.isEmpty() && elem.first[0] == separator[0]) {
             es.emplace_back(
                     OUString(
                         elem.first.getStr() + 1, elem.first.getLength() - 1,
@@ -190,18 +186,17 @@ ActivePackages::Entries ActivePackages::getEntries() const {
 
 void ActivePackages::put(OUString const & id, Data const & data) {
 #if HAVE_FEATURE_EXTENSIONS
-    OStringBuffer b;
-    b.append(
-        OUStringToOString(data.temporaryName, RTL_TEXTENCODING_UTF8));
-    b.append(separator);
-    b.append(OUStringToOString(data.fileName, RTL_TEXTENCODING_UTF8));
-    b.append(separator);
-    b.append(OUStringToOString(data.mediaType, RTL_TEXTENCODING_UTF8));
-    b.append(separator);
-    b.append(OUStringToOString(data.version, RTL_TEXTENCODING_UTF8));
-    b.append(separator);
-    b.append(OUStringToOString(data.failedPrerequisites, RTL_TEXTENCODING_UTF8));
-    m_map.put(newKey(id), b.makeStringAndClear());
+    OString b =
+        OUStringToOString(data.temporaryName, RTL_TEXTENCODING_UTF8) +
+        separator +
+        OUStringToOString(data.fileName, RTL_TEXTENCODING_UTF8) +
+        separator +
+        OUStringToOString(data.mediaType, RTL_TEXTENCODING_UTF8) +
+        separator +
+        OUStringToOString(data.version, RTL_TEXTENCODING_UTF8) +
+        separator +
+        OUStringToOString(data.failedPrerequisites, RTL_TEXTENCODING_UTF8);
+    m_map.put(newKey(id), b);
 #else
     (void) id;
     (void) data;
diff --git a/desktop/source/deployment/registry/component/dp_component.cxx b/desktop/source/deployment/registry/component/dp_component.cxx
index 42de7f9dd042..54ac54daa987 100644
--- a/desktop/source/deployment/registry/component/dp_component.cxx
+++ b/desktop/source/deployment/registry/component/dp_component.cxx
@@ -916,14 +916,13 @@ void BackendImpl::unorc_flush( Reference<XCommandEnvironment> const & xCmdEnv )
             space = true;
 
             // write native rc:
-            OStringBuffer buf2;
-            buf2.append("ORIGIN=");
-            buf2.append(osOrigin);
-            buf2.append(LF);
-            buf2.append( "UNO_SERVICES=?$ORIGIN/" );
-            buf2.append( OUStringToOString(
-                             sNativeRDB, RTL_TEXTENCODING_ASCII_US ) );
-            buf2.append(LF);
+            OString buf2 =
+                "ORIGIN=" +
+                osOrigin +
+                OString(LF) +
+                "UNO_SERVICES=?$ORIGIN/"  +
+                OUStringToOString( sNativeRDB, RTL_TEXTENCODING_ASCII_US ) +
+                OString(LF);
 
             const Reference<io::XInputStream> xData(
                 ::xmlscript::createInputStream(
diff --git a/desktop/source/deployment/registry/dp_backenddb.cxx b/desktop/source/deployment/registry/dp_backenddb.cxx
index 606479447c2a..6361742576b1 100644
--- a/desktop/source/deployment/registry/dp_backenddb.cxx
+++ b/desktop/source/deployment/registry/dp_backenddb.cxx
@@ -156,15 +156,15 @@ void BackendDb::removeEntry(OUString const & url)
 {
     const OUString sKeyElement = getKeyElementName();
     const OUString sPrefix = getNSPrefix();
-    OUStringBuffer sExpression(500);
-    sExpression.append(sPrefix);
-    sExpression.append(":");
-    sExpression.append(sKeyElement);
-    sExpression.append("[@url = \"");
-    sExpression.append(url);
-    sExpression.append("\"]");
-
-    removeElement(sExpression.makeStringAndClear());
+    OUString sExpression =
+        sPrefix +
+        ":" +
+        sKeyElement +
+        "[@url = \"" +
+        url +
+        "\"]";
+
+    removeElement(sExpression);
 }
 
 void BackendDb::revokeEntry(OUString const & url)
@@ -242,18 +242,18 @@ Reference<css::xml::dom::XNode> BackendDb::getKeyElement(
     {
         const OUString sPrefix = getNSPrefix();
         const OUString sKeyElement = getKeyElementName();
-        OUStringBuffer sExpression(500);
-        sExpression.append(sPrefix);
-        sExpression.append(":");
-        sExpression.append(sKeyElement);
-        sExpression.append("[@url = \"");
-        sExpression.append(url);
-        sExpression.append("\"]");
+        OUString sExpression =
+            sPrefix +
+            ":" +
+            sKeyElement +
+            "[@url = \"" +
+            url +
+            "\"]";
 
         const Reference<css::xml::dom::XDocument> doc = getDocument();
         const Reference<css::xml::dom::XNode> root = doc->getFirstChild();
         const Reference<css::xml::xpath::XXPathAPI> xpathApi = getXPathAPI();
-        return xpathApi->selectSingleNode(root, sExpression.makeStringAndClear());
+        return xpathApi->selectSingleNode(root, sExpression);
     }
     catch(const css::uno::Exception &)
     {
@@ -575,18 +575,18 @@ std::vector<OUString> BackendDb::getOneChildFromAllEntries(
         Reference<css::xml::xpath::XXPathAPI> xpathApi = getXPathAPI();
         const OUString sPrefix = getNSPrefix();
         const OUString sKeyElement = getKeyElementName();
-        OUStringBuffer buf(512);
-        buf.append(sPrefix);
-        buf.append(":");
-        buf.append(sKeyElement);
-        buf.append("/");
-        buf.append(sPrefix);
-        buf.append(":");
-        buf.append(name);
-        buf.append("/text()");
+        OUString sNodeSelectExpr =
+            sPrefix +
+            ":" +
+            sKeyElement +
+            "/" +
+            sPrefix +
+            ":" +
+            name +
+            "/text()";
 
         Reference<css::xml::dom::XNodeList> nodes =
-            xpathApi->selectNodeList(root, buf.makeStringAndClear());
+            xpathApi->selectNodeList(root, sNodeSelectExpr);
         if (nodes.is())
         {
             sal_Int32 length = nodes->getLength();
diff --git a/desktop/source/splash/splash.cxx b/desktop/source/splash/splash.cxx
index b5b3568e12e3..c34673f3e881 100644
--- a/desktop/source/splash/splash.cxx
+++ b/desktop/source/splash/splash.cxx
@@ -477,16 +477,13 @@ void SplashScreen::SetScreenBitmap(BitmapEx &rBitmap)
 
     // create file name from screen resolution information
     OStringBuffer aStrBuf( 128 );
-    OStringBuffer aResBuf( 32 );
     aStrBuf.append( "intro_" );
     if ( !_sAppName.isEmpty() )
     {
         aStrBuf.append( OUStringToOString(_sAppName, RTL_TEXTENCODING_UTF8) );
         aStrBuf.append( "_" );
     }
-    aResBuf.append( OString::number( nWidth ));
-    aResBuf.append( "x" );
-    aResBuf.append( OString::number( nHeight ));
+    OString aResBuf = OString::number( nWidth ) + "x" + OString::number( nHeight );
 
     aStrBuf.append( aResBuf.getStr() );
     if (Application::LoadBrandBitmap (aStrBuf.makeStringAndClear().getStr(), rBitmap))
@@ -494,7 +491,7 @@ void SplashScreen::SetScreenBitmap(BitmapEx &rBitmap)
 
     aStrBuf.append( "intro_" );
     aStrBuf.append( aResBuf.getStr() );
-    if (Application::LoadBrandBitmap (aResBuf.makeStringAndClear().getStr(), rBitmap))
+    if (Application::LoadBrandBitmap (aResBuf.getStr(), rBitmap))
         return;
 
     (void)Application::LoadBrandBitmap ("intro", rBitmap);
diff --git a/editeng/source/items/bulitem.cxx b/editeng/source/items/bulitem.cxx
index 46f6271f2c33..97b9b5370064 100644
--- a/editeng/source/items/bulitem.cxx
+++ b/editeng/source/items/bulitem.cxx
@@ -122,10 +122,7 @@ bool SvxBulletItem::operator==( const SfxPoolItem& rItem ) const
 
 OUString SvxBulletItem::GetFullText() const
 {
-    OUStringBuffer aStr(aPrevText);
-    aStr.append(cSymbol);
-    aStr.append(aFollowText);
-    return aStr.makeStringAndClear();
+    return aPrevText + OUStringLiteral1(cSymbol) + aFollowText;
 }
 
 
diff --git a/framework/source/jobs/helponstartup.cxx b/framework/source/jobs/helponstartup.cxx
index 69dc69eacc0d..4233c502d57f 100644
--- a/framework/source/jobs/helponstartup.cxx
+++ b/framework/source/jobs/helponstartup.cxx
@@ -334,14 +334,7 @@ OUString HelpOnStartup::ist_createHelpURL(const OUString& sBaseURL,
                                                  const OUString& sLocale ,
                                                  const OUString& sSystem )
 {
-    OUStringBuffer sHelpURL(256);
-    sHelpURL.append     (sBaseURL    );
-    sHelpURL.append("?Language=");
-    sHelpURL.append     (sLocale     );
-    sHelpURL.append("&System="  );
-    sHelpURL.append     (sSystem     );
-
-    return sHelpURL.makeStringAndClear();
+    return sBaseURL + "?Language=" + sLocale + "&System=" + sSystem;
 }
 
 } // namespace framework
diff --git a/framework/source/layoutmanager/toolbarlayoutmanager.cxx b/framework/source/layoutmanager/toolbarlayoutmanager.cxx
index d0bbafde032c..e5484c7ed4c7 100644
--- a/framework/source/layoutmanager/toolbarlayoutmanager.cxx
+++ b/framework/source/layoutmanager/toolbarlayoutmanager.cxx
@@ -974,11 +974,9 @@ void ToolbarLayoutManager::childWindowEvent( VclSimpleEvent const * pEvent )
                     OUString aToolbarName = retrieveToolbarNameFromHelpURL( pToolBox );
                     if ( !aToolbarName.isEmpty() )
                     {
-                        OUStringBuffer aBuf(100);
-                        aBuf.append( "private:resource/toolbar/" );
-                        aBuf.append( aToolbarName );
+                        OUString aToolbarUrl =  "private:resource/toolbar/" + aToolbarName;
 
-                        UIElement aToolbar = implts_findToolbar( aBuf.makeStringAndClear() );
+                        UIElement aToolbar = implts_findToolbar( aToolbarUrl );
                         if ( aToolbar.m_xUIElement.is() && !aToolbar.m_bFloating )
                         {
                             implts_setLayoutDirty();
diff --git a/framework/source/services/desktop.cxx b/framework/source/services/desktop.cxx
index 1a1352bcf526..c2cf82709ad1 100644
--- a/framework/source/services/desktop.cxx
+++ b/framework/source/services/desktop.cxx
@@ -116,14 +116,12 @@ void Desktop::constructorInit()
     InterceptionHelper* pInterceptionHelper = new InterceptionHelper( this, xDispatchProvider );
     m_xDispatchHelper.set( static_cast< ::cppu::OWeakObject* >(pInterceptionHelper), css::uno::UNO_QUERY );
 
-    OUStringBuffer sUntitledPrefix (256);
-    sUntitledPrefix.append      (FwkResId(STR_UNTITLED_DOCUMENT));
-    sUntitledPrefix.append (" ");
+    OUString sUntitledPrefix = FwkResId(STR_UNTITLED_DOCUMENT) + " ";
 
     ::comphelper::NumberedCollection* pNumbers = new ::comphelper::NumberedCollection ();
     m_xTitleNumberGenerator.set(static_cast< ::cppu::OWeakObject* >(pNumbers), css::uno::UNO_QUERY_THROW);
     pNumbers->setOwner          ( static_cast< ::cppu::OWeakObject* >(this) );
-    pNumbers->setUntitledPrefix ( sUntitledPrefix.makeStringAndClear ()     );
+    pNumbers->setUntitledPrefix ( sUntitledPrefix );
 
     // Safe impossible cases
     // We can't work without this helper!
diff --git a/i18npool/source/breakiterator/breakiteratorImpl.cxx b/i18npool/source/breakiterator/breakiteratorImpl.cxx
index 41ef28fe0162..30a2d9105459 100644
--- a/i18npool/source/breakiterator/breakiteratorImpl.cxx
+++ b/i18npool/source/breakiterator/breakiteratorImpl.cxx
@@ -581,27 +581,26 @@ BreakIteratorImpl::getLocaleSpecificBreakIterator(const Locale& rLocale)
                 return xBI = listItem.xBI;
         }
 
-        sal_Unicode under = '_';
+        OUStringLiteral under("_");
 
         sal_Int32 l = rLocale.Language.getLength();
         sal_Int32 c = rLocale.Country.getLength();
         sal_Int32 v = rLocale.Variant.getLength();
-        OUStringBuffer aBuf(l+c+v+3);
 
         if ((l > 0 && c > 0 && v > 0 &&
                     // load service with name <base>_<lang>_<country>_<variant>
-                    createLocaleSpecificBreakIterator(aBuf.append(rLocale.Language).append(under).append(
-                            rLocale.Country).append(under).append(rLocale.Variant).makeStringAndClear())) ||
+                    createLocaleSpecificBreakIterator(rLocale.Language + under +
+                            rLocale.Country + under + rLocale.Variant)) ||
                 (l > 0 && c > 0 &&
                  // load service with name <base>_<lang>_<country>
-                 createLocaleSpecificBreakIterator(aBuf.append(rLocale.Language).append(under).append(
-                         rLocale.Country).makeStringAndClear())) ||
+                 createLocaleSpecificBreakIterator(rLocale.Language + under +
+                         rLocale.Country)) ||
                 (l > 0 && c > 0 && rLocale.Language == "zh" &&
                  (rLocale.Country == "HK" ||
                   rLocale.Country == "MO" ) &&
                  // if the country code is HK or MO, one more step to try TW.
-                 createLocaleSpecificBreakIterator(aBuf.append(rLocale.Language).append(under).append(
-                         "TW").makeStringAndClear())) ||
+                 createLocaleSpecificBreakIterator(rLocale.Language + under +
+                         "TW")) ||
                 (l > 0 &&
                  // load service with name <base>_<lang>
                  createLocaleSpecificBreakIterator(rLocale.Language)) ||
diff --git a/i18npool/source/breakiterator/breakiterator_unicode.cxx b/i18npool/source/breakiterator/breakiterator_unicode.cxx
index 6312d1feecd5..fee0b19dae38 100644
--- a/i18npool/source/breakiterator/breakiterator_unicode.cxx
+++ b/i18npool/source/breakiterator/breakiterator_unicode.cxx
@@ -195,10 +195,7 @@ void BreakIterator_Unicode::loadICUBreakIterator(const css::lang::Locale& rLocal
                 }
 
                 status = U_ZERO_ERROR;
-                OStringBuffer aUDName(64);
-                aUDName.append(rule);
-                aUDName.append('_');
-                aUDName.append( aLanguage);
+                OString aUDName = rtl::OStringView(rule) + "_" + aLanguage;
                 UDataMemory* pUData = udata_open("OpenOffice", "brk", aUDName.getStr(), &status);
                 if( U_SUCCESS(status) )
                     rbi.reset(new OOoRuleBasedBreakIterator( pUData, status));
diff --git a/include/rtl/stringconcat.hxx b/include/rtl/stringconcat.hxx
index c075a29d9c80..96b018d23d7a 100644
--- a/include/rtl/stringconcat.hxx
+++ b/include/rtl/stringconcat.hxx
@@ -497,6 +497,7 @@ struct ToStringHelper< OUStringNumber< T > >
 class OStringView {
 public:
     explicit OStringView(char const * s): view_(s) {}
+    explicit OStringView(char const * s, size_t len): view_(s, len) {}
 
     std::size_t length() const { return view_.length(); }
 
@@ -518,6 +519,7 @@ struct ToStringHelper< OStringView >
 class OUStringView {
 public:
     explicit OUStringView(sal_Unicode const * s): view_(s) {}
+    explicit OUStringView(sal_Unicode const * s, size_t len): view_(s, len) {}
 
     std::size_t length() const { return view_.length(); }
 
diff --git a/sc/source/core/tool/addincol.cxx b/sc/source/core/tool/addincol.cxx
index 59a7cb6bb648..56e2c421d8c8 100644
--- a/sc/source/core/tool/addincol.cxx
+++ b/sc/source/core/tool/addincol.cxx
@@ -389,11 +389,7 @@ void ScUnoAddInCollection::ReadConfiguration()
             ppFuncData[nFuncPos+nOld] = nullptr;
 
             // stored function name: (service name).(function)
-            OUStringBuffer aFuncNameBuffer( aServiceName.getLength()+1+pFuncNameArray[nFuncPos].getLength());
-            aFuncNameBuffer.append(aServiceName);
-            aFuncNameBuffer.append('.');
-            aFuncNameBuffer.append(pFuncNameArray[nFuncPos]);
-            OUString aFuncName = aFuncNameBuffer.makeStringAndClear();
+            OUString aFuncName = aServiceName + "." + pFuncNameArray[nFuncPos];
 
             // skip the function if already known (read from old AddIn service)
 
@@ -786,11 +782,7 @@ void ScUnoAddInCollection::ReadFromAddIn( const uno::Reference<uno::XInterface>&
                             OUString aFuncU = xFunc->getName();
 
                             // stored function name: (service name).(function)
-                            OUStringBuffer aFuncNameBuffer( aServiceName.getLength()+1+aFuncU.getLength());
-                            aFuncNameBuffer.append(aServiceName);
-                            aFuncNameBuffer.append('.');
-                            aFuncNameBuffer.append(aFuncU);
-                            OUString aFuncName = aFuncNameBuffer.makeStringAndClear();
+                            OUString aFuncName = aServiceName + "." + aFuncU;
 
                             bool bValid = true;
                             long nVisibleCount = 0;
@@ -988,11 +980,7 @@ void ScUnoAddInCollection::UpdateFromAddIn( const uno::Reference<uno::XInterface
                 OUString aFuncU = xFunc->getName();
 
                 // stored function name: (service name).(function)
-                OUStringBuffer aFuncNameBuffer( rServiceName.getLength()+1+aFuncU.getLength());
-                aFuncNameBuffer.append(rServiceName);
-                aFuncNameBuffer.append('.');
-                aFuncNameBuffer.append(aFuncU);
-                OUString aFuncName = aFuncNameBuffer.makeStringAndClear();
+                OUString aFuncName = rServiceName + "." + aFuncU;
 
                 // internal names are skipped because no FuncData exists
                 ScUnoAddInFuncData* pOldData = const_cast<ScUnoAddInFuncData*>( GetFuncData( aFuncName ) );
diff --git a/sc/source/core/tool/interpr1.cxx b/sc/source/core/tool/interpr1.cxx
index df8821b84531..1c0e0237ad53 100644
--- a/sc/source/core/tool/interpr1.cxx
+++ b/sc/source/core/tool/interpr1.cxx
@@ -9144,7 +9144,7 @@ void ScInterpreter::ScFindB()
         else
         {
             // create a string from sStr starting at nStart
-            OUStringBuffer aBuf( lcl_RightB( aStr, nLen - nStart + 1 ) );
+            OUString aBuf = lcl_RightB( aStr, nLen - nStart + 1 );
             // search aBuf for asStr
             sal_Int32 nPos = aBuf.indexOf( asStr, 0 );
             if ( nPos == -1 )
@@ -9152,7 +9152,7 @@ void ScInterpreter::ScFindB()
             else
             {
                 // obtain byte value of nPos
-                int nBytePos = lcl_getLengthB( aBuf.makeStringAndClear(), nPos );
+                int nBytePos = lcl_getLengthB( aBuf, nPos );
                 PushDouble( nBytePos + nStart );
             }
         }
diff --git a/sc/source/core/tool/unitconv.cxx b/sc/source/core/tool/unitconv.cxx
index 354c1ca5ab36..9451db9c1809 100644
--- a/sc/source/core/tool/unitconv.cxx
+++ b/sc/source/core/tool/unitconv.cxx
@@ -37,10 +37,7 @@ ScUnitConverterData::ScUnitConverterData(
 OUString ScUnitConverterData::BuildIndexString(
     const OUString& rFromUnit, const OUString& rToUnit )
 {
-    OUStringBuffer aBuf(rFromUnit);
-    aBuf.append(cDelim);
-    aBuf.append(rToUnit);
-    return aBuf.makeStringAndClear();
+    return rFromUnit + OUStringLiteral1(cDelim) + rToUnit;
 }
 
 // ScUnitConverter
diff --git a/sc/source/filter/excel/xehelper.cxx b/sc/source/filter/excel/xehelper.cxx
index aeffdfa0b4c2..a6e41f742ed8 100644
--- a/sc/source/filter/excel/xehelper.cxx
+++ b/sc/source/filter/excel/xehelper.cxx
@@ -975,9 +975,7 @@ OUString XclExpUrlHelper::EncodeUrl( const XclExpRoot& rRoot, const OUString& rA
 
 OUString XclExpUrlHelper::EncodeDde( const OUString& rApplic, const OUString& rTopic )
 {
-    OUStringBuffer aBuf;
-    aBuf.append(rApplic).append(EXC_DDE_DELIM).append(rTopic);
-    return aBuf.makeStringAndClear();
+    return rApplic + OUStringLiteral1(EXC_DDE_DELIM) + rTopic;
 }
 
 // Cached Value Lists =========================================================
diff --git a/sc/source/filter/html/htmlexp.cxx b/sc/source/filter/html/htmlexp.cxx
index 646b3d281c47..f40bea0967b7 100644
--- a/sc/source/filter/html/htmlexp.cxx
+++ b/sc/source/filter/html/htmlexp.cxx
@@ -1064,10 +1064,9 @@ void ScHTMLExport::WriteCell( sc::ColumnBlockPosition& rBlockPos, SCCOL nCol, SC
     if (pNote)
     {
         //create the comment indicator
-        OStringBuffer aStr(OOO_STRING_SVTOOLS_HTML_anchor);
-        aStr.append(' ').append(OOO_STRING_SVTOOLS_HTML_O_class)
-           .append("=\"").append("comment-indicator").append("\"");
-        TAG_ON(aStr.makeStringAndClear().getStr());
+        OString aStr = OOO_STRING_SVTOOLS_HTML_anchor " "
+            OOO_STRING_SVTOOLS_HTML_O_class "=\"comment-indicator\"";
+        TAG_ON(aStr.getStr());
         TAG_OFF(OOO_STRING_SVTOOLS_HTML_anchor);
         OUT_LF();
 
diff --git a/sc/source/ui/view/viewutil.cxx b/sc/source/ui/view/viewutil.cxx
index ee13c2628c8b..2cbc0ec22ffe 100644
--- a/sc/source/ui/view/viewutil.cxx
+++ b/sc/source/ui/view/viewutil.cxx
@@ -148,13 +148,9 @@ bool ScViewUtil::IsActionShown( const ScChangeAction& rAction,
 
     if ( rSettings.HasComment() )
     {
-        OUStringBuffer aBuf(rAction.GetComment());
-        aBuf.append(" (");
         OUString aTmp;
         rAction.GetDescription(aTmp, &rDocument);
-        aBuf.append(aTmp);
-        aBuf.append(')');
-        OUString aComStr = aBuf.makeStringAndClear();
+        OUString aComStr = rAction.GetComment() + " (" + aTmp + ")";
 
         if(!rSettings.IsValidComment(&aComStr))
             return false;
diff --git a/sd/source/ui/unoidl/UnoDocumentSettings.cxx b/sd/source/ui/unoidl/UnoDocumentSettings.cxx
index 666122868a57..b765dc59a0dc 100644
--- a/sd/source/ui/unoidl/UnoDocumentSettings.cxx
+++ b/sd/source/ui/unoidl/UnoDocumentSettings.cxx
@@ -362,9 +362,9 @@ uno::Sequence<beans::PropertyValue>
                 {
                     // Such specific path construction is grim.
 
-                    OUStringBuffer aName( getNameOfType( t ) );
+                    OUString aName( getNameOfType( t ) );
                     OUString aResult;
-                    if( pList->SaveTo( xSubStorage, aName.makeStringAndClear(), &aResult ) )
+                    if( pList->SaveTo( xSubStorage, aName, &aResult ) )
                     {
                         OUString aRealPath = "Settings/" + aResult;
                         aRet[i].Value <<= aRealPath;
diff --git a/sdext/source/pdfimport/misc/pdfihelper.cxx b/sdext/source/pdfimport/misc/pdfihelper.cxx
index 2936a62965d8..3c6c85538158 100644
--- a/sdext/source/pdfimport/misc/pdfihelper.cxx
+++ b/sdext/source/pdfimport/misc/pdfihelper.cxx
@@ -101,10 +101,7 @@ OUString pdfi::getColorString( const rendering::ARGBColor& rCol )
 
 OUString pdfi::getPercentString(double value)
 {
-    OUStringBuffer buf(32);
-    buf.append(value);
-    buf.append("%");
-    return buf.makeStringAndClear();
+    return OUString::number(value) + "%";
 }
 
 OUString pdfi::unitMMString( double fMM )
diff --git a/sdext/source/pdfimport/pdfparse/pdfentries.cxx b/sdext/source/pdfimport/pdfparse/pdfentries.cxx
index 92cb45ab5a12..e57cf3f701b7 100644
--- a/sdext/source/pdfimport/pdfparse/pdfentries.cxx
+++ b/sdext/source/pdfimport/pdfparse/pdfentries.cxx
@@ -428,12 +428,12 @@ PDFObjectRef::~PDFObjectRef()
 
 bool PDFObjectRef::emit( EmitContext& rWriteContext ) const
 {
-    OStringBuffer aBuf( 16 );
-    aBuf.append( ' ' );
-    aBuf.append( sal_Int32( m_nNumber ) );
-    aBuf.append( ' ' );
-    aBuf.append( sal_Int32( m_nGeneration ) );
-    aBuf.append( " R" );
+    OString aBuf =
+        " " +
+        OString::number( sal_Int32( m_nNumber ) ) +
+        " " +
+        OString::number( sal_Int32( m_nGeneration ) ) +
+        " R";
     return rWriteContext.write( aBuf.getStr(), aBuf.getLength() );
 }
 
@@ -806,11 +806,11 @@ bool PDFObject::emit( EmitContext& rWriteContext ) const
     if( pEData )
         pEData->insertXref( m_nNumber, m_nGeneration, rWriteContext.getCurPos() );
 
-    OStringBuffer aBuf( 32 );
-    aBuf.append( sal_Int32( m_nNumber ) );
-    aBuf.append( ' ' );
-    aBuf.append( sal_Int32( m_nGeneration ) );
-    aBuf.append( " obj\n" );
+    OString aBuf =
+        OString::number( sal_Int32( m_nNumber ) ) +
+        " " +
+        OString::number( sal_Int32( m_nGeneration ) ) +
+        " obj\n";
     if( ! rWriteContext.write( aBuf.getStr(), aBuf.getLength() ) )
         return false;
 
@@ -1426,12 +1426,12 @@ bool PDFFile::emit( EmitContext& rWriteContext ) const
 {
     setEmitData(  rWriteContext, new EmitImplData( this ) );
 
-    OStringBuffer aBuf( 32 );
-    aBuf.append( "%PDF-" );
-    aBuf.append( sal_Int32( m_nMajor ) );
-    aBuf.append( '.' );
-    aBuf.append( sal_Int32( m_nMinor ) );
-    aBuf.append( "\n" );
+    OString aBuf =
+        "%PDF-" +
+        OString::number( sal_Int32( m_nMajor ) ) +
+        "." +
+        OString::number( sal_Int32( m_nMinor ) ) +
+        "\n";
     if( ! rWriteContext.write( aBuf.getStr(), aBuf.getLength() ) )
         return false;
     return emitSubElements( rWriteContext );
diff --git a/sdext/source/pdfimport/sax/emitcontext.cxx b/sdext/source/pdfimport/sax/emitcontext.cxx
index 4b1f7de41172..48c91811f23d 100644
--- a/sdext/source/pdfimport/sax/emitcontext.cxx
+++ b/sdext/source/pdfimport/sax/emitcontext.cxx
@@ -60,10 +60,7 @@ SaxEmitter::SaxEmitter( const uno::Reference< xml::sax::XDocumentHandler >& xDoc
         OUString aStr( OStringToOUString( pDir, RTL_TEXTENCODING_UTF8 ) );
         OUString aFileURL;
         osl_getFileURLFromSystemPath( aStr.pData, &aFileURL.pData );
-        OUStringBuffer aBuf( 256 );
-        aBuf.append( aFileURL );
-        aBuf.append( "/pdfimport.xml" );
-        pStream = new osl::File( aBuf.makeStringAndClear() );
+        pStream = new osl::File( aFileURL + "/pdfimport.xml" );
         if( pStream->open( osl_File_OpenFlag_Write | osl_File_OpenFlag_Create ) )
         {
             pStream->open( osl_File_OpenFlag_Write );
@@ -168,10 +165,7 @@ void SaxEmitter::endTag( const char* pTag )
     for( int i = 0; i < nIndent; i++ )
         pStream->write( "    ", 4, nWritten );
 
-    OStringBuffer aBuf( 1024 );
-    aBuf.append( "</" );
-    aBuf.append( pTag );
-    aBuf.append( ">\n" );
+    OString aBuf = "</" + rtl::OStringView(pTag) + ">\n";
     pStream->write( aBuf.getStr(), aBuf.getLength(), nWritten );
     nIndent--;
 #endif
diff --git a/sdext/source/pdfimport/tree/drawtreevisiting.cxx b/sdext/source/pdfimport/tree/drawtreevisiting.cxx
index 3985d07fdeb8..f4376d41af25 100644
--- a/sdext/source/pdfimport/tree/drawtreevisiting.cxx
+++ b/sdext/source/pdfimport/tree/drawtreevisiting.cxx
@@ -813,10 +813,7 @@ void DrawXmlFinalizer::visit( HyperlinkElement&, const std::list< std::unique_pt
 
 static void SetFontsizeProperties(PropertyMap& props, double fontSize)
 {
-    OUStringBuffer aBuf(32);
-    aBuf.append(fontSize * 72 / PDFI_OUTDEV_RESOLUTION);
-    aBuf.append("pt");
-    OUString aFSize = aBuf.makeStringAndClear();
+    OUString aFSize = OUString::number(fontSize * 72 / PDFI_OUTDEV_RESOLUTION) + "pt";
     props["fo:font-size"] = aFSize;
     props["style:font-size-asian"] = aFSize;
     props["style:font-size-complex"] = aFSize;
diff --git a/sdext/source/pdfimport/tree/writertreevisiting.cxx b/sdext/source/pdfimport/tree/writertreevisiting.cxx
index dd30b0f91c61..00cbad2ac47c 100644
--- a/sdext/source/pdfimport/tree/writertreevisiting.cxx
+++ b/sdext/source/pdfimport/tree/writertreevisiting.cxx
@@ -925,10 +925,7 @@ void WriterXmlFinalizer::visit( TextElement& elem, const std::list< std::unique_
         aFontProps[ "style:text-outline" ]  = "true";
     }
     // size
-    OUStringBuffer aBuf( 32 );
-    aBuf.append( rFont.size*72/PDFI_OUTDEV_RESOLUTION );
-    aBuf.append( "pt" );
-    OUString aFSize = aBuf.makeStringAndClear();
+    OUString aFSize = OUString::number( rFont.size*72/PDFI_OUTDEV_RESOLUTION ) + "pt";
     aFontProps[ "fo:font-size" ]            = aFSize;
     aFontProps[ "style:font-size-asian" ]   = aFSize;
     aFontProps[ "style:font-size-complex" ] = aFSize;
diff --git a/sfx2/source/appl/appuno.cxx b/sfx2/source/appl/appuno.cxx
index d5e315147957..e947abd17d61 100644
--- a/sfx2/source/appl/appuno.cxx
+++ b/sfx2/source/appl/appuno.cxx
@@ -257,8 +257,7 @@ void TransformParameters( sal_uInt16 nSlotId, const uno::Sequence<beans::Propert
                 for ( nSub=0; nSub<nSubCount; nSub++ )
                 {
                     // search sub item by name
-                    OStringBuffer aStr;
-                    aStr.append(pSlot->pUnoName).append('.').append(pType->aAttrib[nSub].pName);
+                    OString aStr = rtl::OStringView(pSlot->pUnoName) + "." + pType->aAttrib[nSub].pName;
                     if ( rPropValue.Name.equalsAsciiL(aStr.getStr(), aStr.getLength()) )
                     {
                         sal_uInt8 nSubId = static_cast<sal_uInt8>(static_cast<sal_Int8>(pType->aAttrib[nSub].nAID));
@@ -364,8 +363,7 @@ void TransformParameters( sal_uInt16 nSlotId, const uno::Sequence<beans::Propert
                     for ( sal_uInt16 nSub=0; nSub<nSubCount; nSub++ )
                     {
                         // search sub item by name
-                        OStringBuffer aStr;
-                        aStr.append(rArg.pName).append('.').append(pType->aAttrib[nSub].pName);
+                        OString aStr = rtl::OStringView(rArg.pName) + "." + pType->aAttrib[nSub].pName;
                         if ( rProp.Name.equalsAsciiL(aStr.getStr(), aStr.getLength()) )
                         {
                             // at least one member found ...
diff --git a/sfx2/source/bastyp/frmhtmlw.cxx b/sfx2/source/bastyp/frmhtmlw.cxx
index b36539f3a8c3..09dcd0cfe85c 100644
--- a/sfx2/source/bastyp/frmhtmlw.cxx
+++ b/sfx2/source/bastyp/frmhtmlw.cxx
@@ -120,10 +120,9 @@ void SfxFrameHTMLWriter::Out_DocInfo( SvStream& rStrm, const OUString& rBaseURL,
             if( pIndent )
                 rStrm.WriteCharPtr( pIndent );
 
-            OStringBuffer sOut;
-            sOut.append('<').append(OOO_STRING_SVTOOLS_HTML_base).append(' ')
-                .append(OOO_STRING_SVTOOLS_HTML_O_target).append("=\"");
-            rStrm.WriteOString( sOut.makeStringAndClear() );
+            OString sOut = "<" OOO_STRING_SVTOOLS_HTML_base " "
+                OOO_STRING_SVTOOLS_HTML_O_target "=\"";
+            rStrm.WriteOString( sOut );
             HTMLOutFuncs::Out_String( rStrm, rTarget, eDestEnc, pNonConvertableChars )
                .WriteCharPtr( "\">" );
         }
diff --git a/sfx2/source/dialog/filedlghelper.cxx b/sfx2/source/dialog/filedlghelper.cxx
index 958ff03dc230..ea3d7a821cec 100644
--- a/sfx2/source/dialog/filedlghelper.cxx
+++ b/sfx2/source/dialog/filedlghelper.cxx
@@ -1780,19 +1780,19 @@ void FileDialogHelper_Impl::addFilters( const OUString& rFactory,
     m_nDontFlags |= nDont;
 
     // create the list of filters
-    OUStringBuffer sQuery(256);
-    sQuery.append("getSortedFilterList()");
-    sQuery.append(":module=");
-    sQuery.append(rFactory); // use long name here !
-    sQuery.append(":iflags=");
-    sQuery.append(OUString::number(static_cast<sal_Int32>(m_nMustFlags)));
-    sQuery.append(":eflags=");
-    sQuery.append(OUString::number(static_cast<sal_Int32>(m_nDontFlags)));
+    OUString sQuery =
+        "getSortedFilterList()"
+        ":module=" +
+        rFactory + // use long name here !
+        ":iflags=" +
+        OUString::number(static_cast<sal_Int32>(m_nMustFlags)) +
+        ":eflags=" +
+        OUString::number(static_cast<sal_Int32>(m_nDontFlags));
 
     uno::Reference< XEnumeration > xResult;
     try
     {
-        xResult = xFilterCont->createSubSetEnumerationByQuery(sQuery.makeStringAndClear());
+        xResult = xFilterCont->createSubSetEnumerationByQuery(sQuery);
     }
     catch( const uno::Exception& )
     {
diff --git a/sfx2/source/view/classificationhelper.cxx b/sfx2/source/view/classificationhelper.cxx
index 23e737900614..57c6a50df38f 100644
--- a/sfx2/source/view/classificationhelper.cxx
+++ b/sfx2/source/view/classificationhelper.cxx
@@ -441,8 +441,7 @@ void SfxClassificationHelper::Impl::setStartValidity(SfxClassificationPolicyType
         {
             // The policy left the start date unchanged, replace it with the system time.
             util::DateTime aDateTime = DateTime(DateTime::SYSTEM).GetUNODateTime();
-            OUStringBuffer aBuffer = utl::toISO8601(aDateTime);
-            it->second = aBuffer.toString();
+            it->second = utl::toISO8601(aDateTime);
         }
     }
 }
diff --git a/stoc/source/security/file_policy.cxx b/stoc/source/security/file_policy.cxx
index 9d8edc2bf102..08d97cfdbf44 100644
--- a/stoc/source/security/file_policy.cxx
+++ b/stoc/source/security/file_policy.cxx
@@ -172,11 +172,8 @@ void PolicyReader::assureToken( sal_Unicode token )
     sal_Unicode c = get();
     if (c == token)
         return;
-    OUStringBuffer buf( 16 );
-    buf.append( "expected >" );
-    buf.append( c );
-    buf.append( "<!" );
-    error( buf.makeStringAndClear() );
+    OUString msg = "expected >" + OUStringLiteral1(c) + "<!";
+    error( msg );
 }
 
 OUString PolicyReader::assureQuotedToken()
diff --git a/stoc/source/security/permissions.cxx b/stoc/source/security/permissions.cxx
index ab70ac1e051b..9568602c1fb4 100644
--- a/stoc/source/security/permissions.cxx
+++ b/stoc/source/security/permissions.cxx
@@ -435,11 +435,8 @@ bool RuntimePermission::implies( Permission const & perm ) const
 
 OUString RuntimePermission::toString() const
 {
-    OUStringBuffer buf( 48 );
-    buf.append( "com.sun.star.security.RuntimePermission (name=\"" );
-    buf.append( m_name );
-    buf.append( "\")" );
-    return buf.makeStringAndClear();
+    return "com.sun.star.security.RuntimePermission (name=\"" +
+        m_name + "\")";
 }
 
 
diff --git a/svtools/source/svhtml/htmlout.cxx b/svtools/source/svhtml/htmlout.cxx
index 2a69acfbf725..841ff9f1f65c 100644
--- a/svtools/source/svhtml/htmlout.cxx
+++ b/svtools/source/svhtml/htmlout.cxx
@@ -923,9 +923,8 @@ SvStream& HTMLOutFuncs::Out_Events( SvStream& rStrm,
 
             if( pStr )
             {
-                OStringBuffer sOut;
-                sOut.append(' ').append(pStr).append("=\"");
-                rStrm.WriteOString( sOut.makeStringAndClear() );
+                OString sOut = " " + rtl::OStringView(pStr) + "=\"";
+                rStrm.WriteOString( sOut );
 
                 Out_String( rStrm, pMacro->GetMacName(), eDestEnc, pNonConvertableChars ).WriteChar( '\"' );
             }
diff --git a/sw/source/filter/html/htmlbas.cxx b/sw/source/filter/html/htmlbas.cxx
index aaa7dbbbaa89..7be428fe3957 100644
--- a/sw/source/filter/html/htmlbas.cxx
+++ b/sw/source/filter/html/htmlbas.cxx
@@ -278,14 +278,14 @@ void SwHTMLWriter::OutBasic()
             {
                 bFirst = false;
                 OutNewLine();
-                OStringBuffer sOut;
-                sOut.append('<').append(OOO_STRING_SVTOOLS_HTML_meta)
-                    .append(' ').append(OOO_STRING_SVTOOLS_HTML_O_httpequiv)
-                    .append("=\"")
-                    .append(OOO_STRING_SVTOOLS_HTML_META_content_script_type)
-                    .append("\" ").append(OOO_STRING_SVTOOLS_HTML_O_content)
-                    .append("=\"text/x-");
-                Strm().WriteOString( sOut.makeStringAndClear() );
+                OString sOut =
+                    "<" OOO_STRING_SVTOOLS_HTML_meta
+                    " " OOO_STRING_SVTOOLS_HTML_O_httpequiv
+                    "=\""
+                    OOO_STRING_SVTOOLS_HTML_META_content_script_type
+                    "\" " OOO_STRING_SVTOOLS_HTML_O_content
+                    "=\"text/x-";
+                Strm().WriteOString( sOut );
                 // Entities aren't welcome here
                 Strm().WriteOString( OUStringToOString(sLang, m_eDestEnc) )
                    .WriteCharPtr( "\">" );
diff --git a/sw/source/filter/html/htmlfldw.cxx b/sw/source/filter/html/htmlfldw.cxx
index 0a581c6e06e9..2f153fdd3b79 100644
--- a/sw/source/filter/html/htmlfldw.cxx
+++ b/sw/source/filter/html/htmlfldw.cxx
@@ -509,12 +509,13 @@ Writer& OutHTML_SwFormatField( Writer& rWrt, const SfxPoolItem& rHt )
         if( !bWritten )
         {
             OUString sComment(convertLineEnd(rComment, GetSystemLineEnd()));
-            OStringBuffer sOut;
             // TODO: ???
-            sOut.append('<').append(OOO_STRING_SVTOOLS_HTML_comment)
-                .append(' ').append(OUStringToOString(sComment,
-                    static_cast<SwHTMLWriter&>(rWrt).m_eDestEnc)).append(" -->");
-            rWrt.Strm().WriteOString( sOut.makeStringAndClear() );
+            OString sOut =
+                "<" OOO_STRING_SVTOOLS_HTML_comment
+                " " +
+                OUStringToOString(sComment, static_cast<SwHTMLWriter&>(rWrt).m_eDestEnc) +
+                " -->";
+            rWrt.Strm().WriteOString( sOut );
         }
     }
     else if( SwFieldIds::Script == pFieldTyp->Which() )
diff --git a/sw/source/filter/html/htmlflywriter.cxx b/sw/source/filter/html/htmlflywriter.cxx
index 8f2465c06871..09d9593a5f12 100644
--- a/sw/source/filter/html/htmlflywriter.cxx
+++ b/sw/source/filter/html/htmlflywriter.cxx
@@ -1660,11 +1660,11 @@ static Writer& OutHTML_FrameFormatAsSpacer( Writer& rWrt, const SwFrameFormat& r
     if( rHTMLWrt.m_bLFPossible )
         rHTMLWrt.OutNewLine( true );
 
-    OStringBuffer sOut;
-    sOut.append('<').append(OOO_STRING_SVTOOLS_HTML_spacer).append(' ')
-        .append(OOO_STRING_SVTOOLS_HTML_O_type).append("=\"")
-        .append(OOO_STRING_SVTOOLS_HTML_SPTYPE_block).append("\"");
-    rWrt.Strm().WriteOString( sOut.makeStringAndClear() );
+    OString sOut =
+        "<" OOO_STRING_SVTOOLS_HTML_spacer " "
+        OOO_STRING_SVTOOLS_HTML_O_type "=\""
+        OOO_STRING_SVTOOLS_HTML_SPTYPE_block "\"";
+    rWrt.Strm().WriteOString( sOut );
 
     // ALIGN, WIDTH, HEIGHT
     OString aEndTags = rHTMLWrt.OutFrameFormatOptions(rFrameFormat, OUString(), HTML_FRMOPTS_SPACER);
diff --git a/sw/source/filter/html/htmlftn.cxx b/sw/source/filter/html/htmlftn.cxx
index 85b5ffcb057e..f0f2f6c5ac0f 100644
--- a/sw/source/filter/html/htmlftn.cxx
+++ b/sw/source/filter/html/htmlftn.cxx
@@ -333,10 +333,10 @@ void SwHTMLWriter::OutFootEndNotes()
 
         if( m_bLFPossible )
             OutNewLine();
-        OStringBuffer sOut;
-        sOut.append('<').append(OOO_STRING_SVTOOLS_HTML_division)
-            .append(' ').append(OOO_STRING_SVTOOLS_HTML_O_id).append("=\"");
-        Strm().WriteOString( sOut.makeStringAndClear() );
+        OString sOut =
+            "<" OOO_STRING_SVTOOLS_HTML_division
+            " " OOO_STRING_SVTOOLS_HTML_O_id "=\"";
+        Strm().WriteOString( sOut );
         HTMLOutFuncs::Out_String( Strm(), sFootnoteName, m_eDestEnc, &m_aNonConvertableCharacters );
         Strm().WriteCharPtr( "\">" );
 
@@ -510,11 +510,11 @@ static void lcl_html_outFootEndNoteInfo( Writer& rWrt, OUString const *pParts,
     }
 
     rHTMLWrt.OutNewLine();
-    OStringBuffer sOut;
-    sOut.append('<').append(OOO_STRING_SVTOOLS_HTML_meta).append(' ')
-        .append(OOO_STRING_SVTOOLS_HTML_O_name).append("=\"").append(pName)
-        .append("\" ").append(OOO_STRING_SVTOOLS_HTML_O_content).append("=\"");
-    rWrt.Strm().WriteOString( sOut.makeStringAndClear() );
+    OString sOut =
+        "<" OOO_STRING_SVTOOLS_HTML_meta " "
+        OOO_STRING_SVTOOLS_HTML_O_name "=\"" + rtl::OStringView(pName) +
+        "\" " OOO_STRING_SVTOOLS_HTML_O_content "=\"";
+    rWrt.Strm().WriteOString( sOut );
     HTMLOutFuncs::Out_String( rWrt.Strm(), aContent.makeStringAndClear(), rHTMLWrt.m_eDestEnc, &rHTMLWrt.m_aNonConvertableCharacters );
     rWrt.Strm().WriteCharPtr( "\">" );
 }
diff --git a/sw/source/filter/html/htmltabw.cxx b/sw/source/filter/html/htmltabw.cxx
index da33a4bbb6eb..c0ce2183f00a 100644
--- a/sw/source/filter/html/htmltabw.cxx
+++ b/sw/source/filter/html/htmltabw.cxx
@@ -1063,9 +1063,9 @@ Writer& OutHTML_SwTableNode( Writer& rWrt, SwTableNode & rNode,
             HTMLOutFuncs::Out_AsciiTag( rWrt.Strm(), rHTMLWrt.GetNamespace() + OOO_STRING_SVTOOLS_HTML_center );
         else
         {
-            OStringBuffer sOut(OOO_STRING_SVTOOLS_HTML_division);
-            sOut.append(' ').append(OOO_STRING_SVTOOLS_HTML_O_align).append("=\"")
-                .append(OOO_STRING_SVTOOLS_HTML_AL_right).append("\"");
+            OString sOut = OOO_STRING_SVTOOLS_HTML_division
+                " " OOO_STRING_SVTOOLS_HTML_O_align "=\""
+                OOO_STRING_SVTOOLS_HTML_AL_right "\"";
             HTMLOutFuncs::Out_AsciiTag( rWrt.Strm(), rHTMLWrt.GetNamespace() + sOut.getStr() );
         }
         rHTMLWrt.IncIndentLevel();  // indent content of <CENTER>
diff --git a/sw/source/filter/html/wrthtml.cxx b/sw/source/filter/html/wrthtml.cxx
index 2ccdcc932ab9..9fc8d8298dd5 100644
--- a/sw/source/filter/html/wrthtml.cxx
+++ b/sw/source/filter/html/wrthtml.cxx
@@ -410,12 +410,11 @@ ErrCode SwHTMLWriter::WriteStream()
                     pSNd->GetSection().GetSectionName(), m_eDestEnc,
                     &m_aNonConvertableCharacters );
 
-                OStringBuffer sOut;
-                sOut.append('<').append(OOO_STRING_SVTOOLS_HTML_division)
-                    .append(' ').append(OOO_STRING_SVTOOLS_HTML_O_id)
-                    .append("=\"").append(aName).append('\"').append('>')
-                    .append(aStartTags);
-                aStartTags = sOut.makeStringAndClear();
+                aStartTags =
+                    "<" OOO_STRING_SVTOOLS_HTML_division
+                    " " OOO_STRING_SVTOOLS_HTML_O_id
+                    "=\"" + aName + "\">" +
+                    aStartTags;
             }
             // FindSectionNode() on a SectionNode return the same!
             pSNd = pSNd->StartOfSectionNode()->FindSectionNode();
@@ -1261,9 +1260,9 @@ void SwHTMLWriter::OutBackground( const SvxBrushItem *pBrushItem, bool bGraphic
     /// only checking, if transparency is not set.
     if( rBackColor != COL_TRANSPARENT )
     {
-        OStringBuffer sOut;
-        sOut.append(' ').append(OOO_STRING_SVTOOLS_HTML_O_bgcolor).append('=');
-        Strm().WriteOString( sOut.makeStringAndClear() );
+        OString sOut =
+            " " OOO_STRING_SVTOOLS_HTML_O_bgcolor "=";
+        Strm().WriteOString( sOut );
         HTMLOutFuncs::Out_Color( Strm(), rBackColor);
     }
 
@@ -1375,10 +1374,10 @@ void SwHTMLWriter::OutDirection( SvxFrameDirection nDir )
     OString sConverted = convertDirection(nDir);
     if (!sConverted.isEmpty())
     {
-        OStringBuffer sOut;
-        sOut.append(' ').append(OOO_STRING_SVTOOLS_HTML_O_dir)
-            .append("=\"").append(sConverted).append('\"');
-        Strm().WriteOString( sOut.makeStringAndClear() );
+        OString sOut =
+            " " OOO_STRING_SVTOOLS_HTML_O_dir
+            "=\"" + sConverted + "\"";
+        Strm().WriteOString( sOut );
     }
 }
 
diff --git a/sw/source/uibase/app/applab.cxx b/sw/source/uibase/app/applab.cxx
index da1e18009143..d59ad9cd171e 100644
--- a/sw/source/uibase/app/applab.cxx
+++ b/sw/source/uibase/app/applab.cxx
@@ -340,11 +340,11 @@ void SwModule::InsertLab(SfxRequest& rReq, bool bLabel)
                     {
                         SwSectionData aSect(FILE_LINK_SECTION,
                                 pSh->GetUniqueSectionName());
-                        OUStringBuffer sLinkName;
-                        sLinkName.append(sfx2::cTokenSeparator);
-                        sLinkName.append(sfx2::cTokenSeparator);
-                        sLinkName.append(MASTER_LABEL);
-                        aSect.SetLinkFileName(sLinkName.makeStringAndClear());
+                        OUString sLinkName =
+                            OUStringLiteral1(sfx2::cTokenSeparator) +
+                            OUStringLiteral1(sfx2::cTokenSeparator) +
+                            MASTER_LABEL;
+                        aSect.SetLinkFileName(sLinkName);
                         aSect.SetProtectFlag(true);
                         pSh->Insert(".");   // Dummytext to allocate the Section
                         pSh->StartOfSection();
diff --git a/tools/source/fsys/urlobj.cxx b/tools/source/fsys/urlobj.cxx
index 37f3791a4d30..91fe51a9e283 100644
--- a/tools/source/fsys/urlobj.cxx
+++ b/tools/source/fsys/urlobj.cxx
@@ -4193,12 +4193,11 @@ bool INetURLObject::removeExtension(sal_Int32 nIndex, bool bIgnoreFinalSlash)
     if (!pExtension)
         return true;
 
-    OUStringBuffer aNewPath;
-    aNewPath.append(pPathBegin, pExtension - pPathBegin);
-    aNewPath.append(p, pPathEnd - p);
+    OUString aNewPath =
+        rtl::OUStringView(pPathBegin, pExtension - pPathBegin) +
+        rtl::OUStringView(p, pPathEnd - p);
 
-    return setPath(aNewPath.makeStringAndClear(), EncodeMechanism::NotCanonical,
-        RTL_TEXTENCODING_UTF8);
+    return setPath(aNewPath, EncodeMechanism::NotCanonical, RTL_TEXTENCODING_UTF8);
 }
 
 bool INetURLObject::hasFinalSlash() const
@@ -4223,12 +4222,9 @@ bool INetURLObject::setFinalSlash()
     if (pPathEnd > pPathBegin && pPathEnd[-1] == '/')
         return true;
 
-    OUStringBuffer aNewPath;
-    aNewPath.append(pPathBegin, pPathEnd - pPathBegin);
-    aNewPath.append('/');
+    OUString aNewPath = rtl::OUStringView(pPathBegin, pPathEnd - pPathBegin) + "/";
 
-    return setPath(aNewPath.makeStringAndClear(), EncodeMechanism::NotCanonical,
-        RTL_TEXTENCODING_UTF8);
+    return setPath(aNewPath, EncodeMechanism::NotCanonical, RTL_TEXTENCODING_UTF8);
 }
 
 bool INetURLObject::removeFinalSlash()
diff --git a/vcl/source/gdi/pdfwriter_impl.cxx b/vcl/source/gdi/pdfwriter_impl.cxx
index 47d90025172a..b2c885086ead 100644
--- a/vcl/source/gdi/pdfwriter_impl.cxx
+++ b/vcl/source/gdi/pdfwriter_impl.cxx
@@ -367,11 +367,7 @@ void PDFWriterImpl::createWidgetFieldName( sal_Int32 i_nWidgetIndex, const PDFWr
                 if( nLastTokenIndex > 0 )
                 {
                     aDomain = aFullName.copy( 0, nLastTokenIndex-1 );
-                    OStringBuffer aBuf( aDomain.getLength() + 1 + aPartialName.getLength() );
-                    aBuf.append( aDomain );
-                    aBuf.append( '.' );
-                    aBuf.append( aPartialName );
-                    aFullName = aBuf.makeStringAndClear();
+                    aFullName = aDomain + "." + aPartialName;
                 }
                 else
                     aFullName = aPartialName;
@@ -1666,10 +1662,7 @@ void PDFWriterImpl::appendLiteralStringEncrypt( const OUString& rInString, const
 
 void PDFWriterImpl::emitComment( const char* pComment )
 {
-    OStringBuffer aLine( 64 );
-    aLine.append( "% " );
-    aLine.append( pComment );
-    aLine.append( "\n" );
+    OString aLine = "% " + rtl::OStringView(pComment) + "\n";
     writeBuffer( aLine.getStr(), aLine.getLength() );
 }
 
@@ -2016,23 +2009,22 @@ OString PDFWriterImpl::emitStructureAttributes( PDFStructureElement& i_rEle )
             if( nLink >= 0 && nLink < static_cast<sal_Int32>(m_aLinks.size()) )
             {
                 // update struct parent of link
-                OStringBuffer aStructParentEntry( 32 );
-                aStructParentEntry.append( i_rEle.m_nObject );
-                aStructParentEntry.append( " 0 R" );
-                m_aStructParentTree.push_back( aStructParentEntry.makeStringAndClear() );
+                OString aStructParentEntry =
+                    OString::number( i_rEle.m_nObject ) +
+                    " 0 R";
+                m_aStructParentTree.push_back( aStructParentEntry );
                 m_aLinks[ nLink ].m_nStructParent = m_aStructParentTree.size()-1;
 
                 sal_Int32 nRefObject = createObject();
-                OStringBuffer aRef( 256 );
-                aRef.append( nRefObject );
-                aRef.append( " 0 obj\n"
-                             "<</Type/OBJR/Obj " );
-                aRef.append( m_aLinks[ nLink ].m_nObject );
-                aRef.append( " 0 R>>\n"
-                             "endobj\n\n"
-                             );
                 if (updateObject(nRefObject))
                 {
+                    OString aRef =
+                        OString::number( nRefObject ) +
+                        " 0 obj\n"
+                        "<</Type/OBJR/Obj " +
+                        OString::number( m_aLinks[ nLink ].m_nObject ) +
+                        " 0 R>>\n"
+                        "endobj\n\n";
                     writeBuffer( aRef.getStr(), aRef.getLength() );
                 }
 
@@ -3806,8 +3798,7 @@ void PDFWriterImpl::createDefaultEditAppearance( PDFWidget& rEdit, const PDFWrit
         relies on /NeedAppearances in the AcroForm dictionary set to "true"
      */
     beginRedirect( pEditStream, rEdit.m_aRect );
-    OStringBuffer aAppearance( 32 );
-    aAppearance.append( "/Tx BMC\nEMC\n" );
+    OString aAppearance = "/Tx BMC\nEMC\n";
     writeBuffer( aAppearance.getStr(), aAppearance.getLength() );
 
     endRedirect();
@@ -3830,14 +3821,13 @@ void PDFWriterImpl::createDefaultListBoxAppearance( PDFWidget& rBox, const PDFWr
     sal_Int32 nBest = getSystemFont( aFont );
 
     beginRedirect( pListBoxStream, rBox.m_aRect );
-    OStringBuffer aAppearance( 64 );
 
     setLineColor( COL_TRANSPARENT );
     setFillColor( replaceColor( rWidget.BackgroundColor, rSettings.GetFieldColor() ) );
     drawRectangle( rBox.m_aRect );
 
     // empty appearance, see createDefaultEditAppearance for reference
-    aAppearance.append( "/Tx BMC\nEMC\n" );
+    OString aAppearance = "/Tx BMC\nEMC\n";
     writeBuffer( aAppearance.getStr(), aAppearance.getLength() );
 
     endRedirect();
@@ -4940,9 +4930,7 @@ bool PDFWriterImpl::finalizeSignature()
     // 2- overwrite the value to the m_nSignatureLastByteRangeNoOffset position
     sal_uInt64 nWritten = 0;
     CHECK_RETURN( (osl::File::E_None == m_aFile.setPos(osl_Pos_Absolut, m_nSignatureLastByteRangeNoOffset) ) );
-    OStringBuffer aByteRangeNo( 256 );
-    aByteRangeNo.append( nLastByteRangeNo );
-    aByteRangeNo.append( " ]" );
+    OString aByteRangeNo = OString::number( nLastByteRangeNo ) + " ]";
 
     if (m_aFile.write(aByteRangeNo.getStr(), aByteRangeNo.getLength(), nWritten) != osl::File::E_None)
     {
@@ -7423,13 +7411,13 @@ void PDFWriterImpl::drawTransparent( const tools::PolyPolygon& rPolyPoly, sal_uI
     aObjName.append( m_aTransparentObjects.back().m_nExtGStateObject );
     OString aExtName( aObjName.makeStringAndClear() );
 
-    OStringBuffer aLine( 80 );
+    OString aLine =
     // insert XObject
-    aLine.append( "q /" );
-    aLine.append( aExtName );
-    aLine.append( " gs /" );
-    aLine.append( aTrName );
-    aLine.append( " Do Q\n" );
+        "q /" +
+        aExtName +
+        " gs /" +
+        aTrName +
+        " Do Q\n";
     writeBuffer( aLine.getStr(), aLine.getLength() );
 
     pushResource( ResXObject, aTrName, m_aTransparentObjects.back().m_nObject );
@@ -7556,13 +7544,13 @@ void PDFWriterImpl::endTransparencyGroup( const tools::Rectangle& rBoundingBox,
     aObjName.append( m_aTransparentObjects.back().m_nExtGStateObject );
     OString aExtName( aObjName.makeStringAndClear() );
 
-    OStringBuffer aLine( 80 );
+    OString aLine =
     // insert XObject
-    aLine.append( "q /" );
-    aLine.append( aExtName );
-    aLine.append( " gs /" );
-    aLine.append( aTrName );
-    aLine.append( " Do Q\n" );
+        "q /" +
+        aExtName +
+        " gs /" +
+        aTrName +
+        " Do Q\n";
     writeBuffer( aLine.getStr(), aLine.getLength() );
 
     pushResource( ResXObject, aTrName, m_aTransparentObjects.back().m_nObject );
@@ -9443,10 +9431,8 @@ void PDFWriterImpl::drawJPGBitmap( SvStream& rDCTData, bool bIsTrueColor, const
     }
     writeBuffer( aLine.getStr(), aLine.getLength() );
 
-    OStringBuffer aObjName( 16 );
-    aObjName.append( "Im" );
-    aObjName.append(nObject);
-    pushResource( ResXObject, aObjName.makeStringAndClear(), nObject );
+    OString aObjName = "Im" + OString::number(nObject);
+    pushResource( ResXObject, aObjName, nObject );
 
 }
 
@@ -9521,11 +9507,9 @@ const PDFWriterImpl::BitmapEmit& PDFWriterImpl::createBitmapEmit( const BitmapEx
         it = m_aBitmaps.begin();
     }
 
-    OStringBuffer aObjName( 16 );
-    aObjName.append( "Im" );
     sal_Int32 nObject = it->m_aReferenceXObject.getObject();
-    aObjName.append(nObject);
-    pushResource( ResXObject, aObjName.makeStringAndClear(), nObject );
+    OString aObjName = "Im" + OString::number(nObject);
+    pushResource( ResXObject, aObjName, nObject );
 
     return *it;
 }
@@ -9727,10 +9711,7 @@ void PDFWriterImpl::drawWallpaper( const tools::Rectangle& rRect, const Wallpape
                 tools::Rectangle aConvertRect( aBmpPos, aBmpSize );
                 m_aPages.back().convertRect( aConvertRect );
 
-                OStringBuffer aNameBuf(16);
-                aNameBuf.append( "Im" );
-                aNameBuf.append( rEmit.m_nObject );
-                OString aImageName( aNameBuf.makeStringAndClear() );
+                OString aImageName = "Im" + OString::number( rEmit.m_nObject );
 
                 // push the pattern
                 OStringBuffer aTilingStream( 32 );
@@ -10345,8 +10326,7 @@ void PDFWriterImpl::beginStructureElementMCSeq()
              ! m_aStructure[ m_nCurrentStructElement ].m_bOpenMCSeq // already opened sequence
              )
     {
-        OStringBuffer aLine( 128 );
-        aLine.append( "/Artifact BMC\n" );
+        OString aLine = "/Artifact BMC\n";
         writeBuffer( aLine.getStr(), aLine.getLength() );
         // mark element MC sequence as open
         m_aStructure[ m_nCurrentStructElement ].m_bOpenMCSeq = true;
diff --git a/vcl/unx/generic/print/printerjob.cxx b/vcl/unx/generic/print/printerjob.cxx
index 73dedc5a2415..7d805ef942e5 100644
--- a/vcl/unx/generic/print/printerjob.cxx
+++ b/vcl/unx/generic/print/printerjob.cxx
@@ -211,18 +211,14 @@ createSpoolDir ()
 
     do
     {
-        OUStringBuffer aDir( aTmpDir.getLength() + 16 );
-        aDir.append( aTmpDir );
-        aDir.append( "/psp" );
-        aDir.append(nRand);
-        OUString aResult = aDir.makeStringAndClear();
-        if( osl::Directory::create( aResult ) == osl::FileBase::E_None )
+        OUString aDir = aTmpDir + "/psp" + OUString::number(nRand);
+        if( osl::Directory::create( aDir ) == osl::FileBase::E_None )
         {
-            osl::File::setAttributes( aResult,
+            osl::File::setAttributes( aDir,
                                         osl_File_Attribute_OwnWrite
                                       | osl_File_Attribute_OwnRead
                                       | osl_File_Attribute_OwnExe );
-            return aResult;
+            return aDir;
         }
         nRand++;
     } while( nRand );
diff --git a/vcl/unx/generic/printer/cpdmgr.cxx b/vcl/unx/generic/printer/cpdmgr.cxx
index 5a2e1b01d271..cae2a4e1ab03 100644
--- a/vcl/unx/generic/printer/cpdmgr.cxx
+++ b/vcl/unx/generic/printer/cpdmgr.cxx
@@ -206,9 +206,6 @@ void CPDManager::addNewPrinter(const OUString& aPrinterName, const OUString& aUn
     rtl_TextEncoding aEncoding = osl_getThreadTextEncoding();
     aPrinter.m_aInfo.m_aComment = OStringToOUString(pDest->info, aEncoding);
     aPrinter.m_aInfo.m_aLocation = OStringToOUString(pDest->location, aEncoding);
-    OUStringBuffer aBuf( 256 );
-    aBuf.append( "CPD:" );
-    aBuf.append( aUniqueName );
     // note: the parser that goes with the PrinterInfo
     // is created implicitly by the JobData::operator=()
     // when it detects the NULL ptr m_pParser.
@@ -225,7 +222,7 @@ void CPDManager::addNewPrinter(const OUString& aPrinterName, const OUString& aUn
         aPrinter.m_aInfo.m_aContext = c_it->second;
     }
     aPrinter.m_aInfo.setDefaultBackend(true);
-    aPrinter.m_aInfo.m_aDriverName = aBuf.makeStringAndClear();
+    aPrinter.m_aInfo.m_aDriverName = "CPD:" + aUniqueName;
     m_aPrinters[ aUniqueName ] = aPrinter;
 }
 #endif
diff --git a/vcl/unx/generic/printer/cupsmgr.cxx b/vcl/unx/generic/printer/cupsmgr.cxx
index a6d1ccbad7bb..12482b2ba878 100644
--- a/vcl/unx/generic/printer/cupsmgr.cxx
+++ b/vcl/unx/generic/printer/cupsmgr.cxx
@@ -312,11 +312,8 @@ void CUPSManager::initialize()
         OUString aPrinterName = OStringToOUString( pDest->name, aEncoding );
         if( pDest->instance && *pDest->instance )
         {
-            OUStringBuffer aBuf( 256 );
-            aBuf.append( aPrinterName );
-            aBuf.append( '/' );
-            aBuf.append( OStringToOUString( pDest->instance, aEncoding ) );
-            aPrinterName = aBuf.makeStringAndClear();
+            aPrinterName += "/" +
+                OStringToOUString( pDest->instance, aEncoding );
         }
 
         // initialize printer with possible configuration from psprint.conf
@@ -338,9 +335,6 @@ void CUPSManager::initialize()
                 aPrinter.m_aInfo.m_aAuthInfoRequired=OStringToOUString(pDest->options[k].value, aEncoding);
         }
 
-        OUStringBuffer aBuf( 256 );
-        aBuf.append( "CUPS:" );
-        aBuf.append( aPrinterName );
         // note: the parser that goes with the PrinterInfo
         // is created implicitly by the JobData::operator=()
         // when it detects the NULL ptr m_pParser.
@@ -357,7 +351,7 @@ void CUPSManager::initialize()
             aPrinter.m_aInfo.m_aContext = c_it->second;
         }
         aPrinter.m_aInfo.setDefaultBackend(bUsePDF);
-        aPrinter.m_aInfo.m_aDriverName = aBuf.makeStringAndClear();
+        aPrinter.m_aInfo.m_aDriverName = "CUPS:" + aPrinterName;
 
         m_aPrinters[ aPrinter.m_aInfo.m_aPrinterName ] = aPrinter;
         m_aCUPSDestMap[ aPrinter.m_aInfo.m_aPrinterName ] = nPrinter;
diff --git a/vcl/unx/generic/printer/ppdparser.cxx b/vcl/unx/generic/printer/ppdparser.cxx
index 0d520e09d219..880a7d958000 100644
--- a/vcl/unx/generic/printer/ppdparser.cxx
+++ b/vcl/unx/generic/printer/ppdparser.cxx
@@ -620,10 +620,10 @@ PPDParser::PPDParser(const OUString& rFile, const std::vector<PPDKey*>& keys)
             pwg_media_t *pPWGMedia = pwgMediaForPWG(o.pData->buffer);
             if (pPWGMedia != nullptr) {
                 OUStringBuffer aBuf( 256 );
-                aBuf.append( "0 0 " );
-                aBuf.append( PWG_TO_POINTS(pPWGMedia -> width) );
-                aBuf.append( " " );
-                aBuf.append( PWG_TO_POINTS(pPWGMedia -> length) );
+                aBuf = "0 0 " +
+                    OUString::number(PWG_TO_POINTS(pPWGMedia -> width)) +
+                    " " +
+                    OUString::number(PWG_TO_POINTS(pPWGMedia -> length));
                 if ( pImageableAreaValue )
                     pImageableAreaValue->m_aValue = aBuf.makeStringAndClear();
                 aBuf.append( PWG_TO_POINTS(pPWGMedia -> width) );
diff --git a/vcl/unx/generic/printer/printerinfomanager.cxx b/vcl/unx/generic/printer/printerinfomanager.cxx
index 1977a80b5e7f..8ba1df9810bb 100644
--- a/vcl/unx/generic/printer/printerinfomanager.cxx
+++ b/vcl/unx/generic/printer/printerinfomanager.cxx
@@ -846,12 +846,10 @@ void SystemQueueInfo::run()
     for(const auto & rParm : aParms)
     {
         aLines.clear();
-        OStringBuffer aCmdLine( 128 );
-        aCmdLine.append( rParm.pQueueCommand );
         #if OSL_DEBUG_LEVEL > 1
         fprintf( stderr, "trying print queue command \"%s\" ... ", rParm.pQueueCommand );
         #endif
-        aCmdLine.append( " 2>/dev/null" );
+        OString aCmdLine = rParm.pQueueCommand + OStringLiteral(" 2>/dev/null");
         FILE *pPipe;
         if( (pPipe = popen( aCmdLine.getStr(), "r" )) )
         {
diff --git a/vcl/unx/generic/window/salframe.cxx b/vcl/unx/generic/window/salframe.cxx
index 370b47cbdb6b..87b795513367 100644
--- a/vcl/unx/generic/window/salframe.cxx
+++ b/vcl/unx/generic/window/salframe.cxx
@@ -2881,10 +2881,7 @@ bool X11SalFrame::appendUnicodeSequence( sal_Unicode c )
             (c >= 'a' && c <= 'f') ||
             (c >= 'A' && c <= 'F') )
         {
-            OUStringBuffer aBuf( rSeq.getLength() + 1 );
-            aBuf.append( rSeq );
-            aBuf.append( c );
-            rSeq = aBuf.makeStringAndClear();
+            rSeq += OUStringLiteral1(c);
             std::vector<ExtTextInputAttr> attribs( rSeq.getLength(), ExtTextInputAttr::Underline );
 
             SalExtTextInputEvent aEv;
diff --git a/vcl/workben/svpclient.cxx b/vcl/workben/svpclient.cxx
index 744b38138239..8ef179b0c1a2 100644
--- a/vcl/workben/svpclient.cxx
+++ b/vcl/workben/svpclient.cxx
@@ -180,11 +180,10 @@ void MyWin::parseList( const OString& rList )
             aElementType = OStringToOUString( aLine.copy( 13 ), RTL_TEXTENCODING_ASCII_US );
         else
         {
-            OUStringBuffer aNewElement( 64 );
-            aNewElement.append( aElementType );
-            aNewElement.append( ": " );
-            aNewElement.append( OStringToOUString( aLine, RTL_TEXTENCODING_ASCII_US ) );
-            m_aSvpBitmaps->InsertEntry( aNewElement.makeStringAndClear() );
+            OUString aNewElement =
+                aElementType + ": " +
+                OStringToOUString( aLine, RTL_TEXTENCODING_ASCII_US );
+            m_aSvpBitmaps->InsertEntry( aNewElement );
         }
     }
 }
diff --git a/vcl/workben/svptest.cxx b/vcl/workben/svptest.cxx
index a79cda4df507..72ff179821a8 100644
--- a/vcl/workben/svptest.cxx
+++ b/vcl/workben/svptest.cxx
@@ -238,13 +238,11 @@ void MyWin::Paint(vcl::RenderContext& rRenderContext, const tools::Rectangle& rR
         sal_uInt8 nBlue  = (i << 2) & 0xC0;
         rRenderContext.SetTextColor(Color(nRed, nGreen, nBlue));
 
-        OUStringBuffer aPrintText(1024);
-
-        aPrintText.append( "SVP test program" );
+        OUString aPrintText = "SVP test program";
 
         rRenderContext.DrawText(tools::Rectangle(Point((aPaperSize.Width() - 4000) / 2, 2000),
                                 Size(aPaperSize.Width() - 2100, aPaperSize.Height() - 4000)),
-                                aPrintText.makeStringAndClear(),
+                                aPrintText,
                                 DrawTextFlags::MultiLine);
     }
 
diff --git a/writerfilter/source/dmapper/TextEffectsHandler.cxx b/writerfilter/source/dmapper/TextEffectsHandler.cxx
index 30fdd7b9cc5b..fcefb30295a3 100644
--- a/writerfilter/source/dmapper/TextEffectsHandler.cxx
+++ b/writerfilter/source/dmapper/TextEffectsHandler.cxx
@@ -514,7 +514,7 @@ void TextEffectsHandler::lcl_attribute(Id aName, Value& aValue)
             break;
         case NS_ooxml::LN_CT_SRgbColor_val:
             {
-                OUStringBuffer aBuffer = OUString::number(aValue.getInt(), 16);
+                OUString aBuffer = OUString::number(aValue.getInt(), 16);
                 OUStringBuffer aString;
                 comphelper::string::padToLength(aString, 6 - aBuffer.getLength(), '0');
                 aString.append(aBuffer.getStr());
diff --git a/xmloff/source/style/xmlnumi.cxx b/xmloff/source/style/xmlnumi.cxx
index 02e58ba4ecad..ed6304d00d84 100644
--- a/xmloff/source/style/xmlnumi.cxx
+++ b/xmloff/source/style/xmlnumi.cxx
@@ -517,10 +517,9 @@ Sequence<beans::PropertyValue> SvxXMLListLevelStyleContext_Impl::GetProperties()
 
             // Must append 'cBullet' even if it is zero
             // if 'bBullet' is true and 'cBullet' is zero - BulletChar property must be 0.
-            OUStringBuffer sTmp(1);
-            sTmp.append( cBullet );
+            OUString sTmp = OUStringLiteral1( cBullet );
             pProps[nPos].Name = "BulletChar";
-            pProps[nPos++].Value <<= sTmp.makeStringAndClear();
+            pProps[nPos++].Value <<= sTmp;
 
             pProps[nPos].Name = "BulletFont";
             pProps[nPos++].Value <<= aFDesc;
@@ -1249,10 +1248,9 @@ void SvxXMLListStyleContext::SetDefaultStyle(
         pProps->Name = "BulletFont";
         (pProps++)->Value <<= aFDesc;
 
-        OUStringBuffer sTmp(1);
-        sTmp.append( sal_Unicode(0xF000 + 149) );
+        OUString sTmp = OUStringLiteral1(sal_Unicode(0xF000 + 149));
         pProps->Name = "BulletChar";
-        (pProps++)->Value <<= sTmp.makeStringAndClear();
+        (pProps++)->Value <<= sTmp;
         pProps->Name = "CharStyleName";
         (pProps++)->Value <<= OUString( "Numbering Symbols"  );
     }