In O[U]StringBuffer, make string_view params replacements for OUString ones

...for LIBO_INTERNAL_ONLY, instead of having them as additional overloads.  That
way, loplugin:bufferadd and loplugin:stringviewparam found many further
opportunities for simplification (all addressed here).  Some notes:

* There is no longer an implicit conversion from O[U]String to O[U]StringBuffer
(as that goes via user-defined conversions through string_view now), which was
most noticeable in copy initializations like

  OStringBuffer buf = someStr;

that had to be changed to direct initialization,

  OStringBuffer buf(someStr);

But then again, it wasn't too many places that were affected and I think we can
live with that.

* I made the O[U]StringBuffer ctors taking string_view non-explicit, mainly to
get them in line with their counterparts taking O[U]String.

* I added an OUStringBuffer::lastIndexOf string_view overload that was missing
(relative to OUStringBuffer::indexOf).

* loplugin:stringconstant needed some addition to keep the
compilerplugins/clang/test/stringconstant.cxx checks related to
OStringBuffer::append and OStringBuffer::insert working.

* loplugin:stringviewparam no longer needs the special O[U]StringBuffer-related
code that had been introduced in 1250aecd71fabde4dba990bfceb61bbe8e06b8ea
"loplugin:stringviewparam extend to new.."

Change-Id: Ib1bb8c4632d99b744e742605a9fef6eae959fd72
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/122904
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

2 files changed, 3 insertions, 8 deletions

diff --git a/starmath/source/mathml/mathmlexport.cxx b/starmath/source/mathml/mathmlexport.cxx
index dedd6532f8a5..0d7ba20396b8 100644
--- a/starmath/source/mathml/mathmlexport.cxx
+++ b/starmath/source/mathml/mathmlexport.cxx
@@ -1158,11 +1158,8 @@ void SmXMLExport::ExportFont(const SmNode* pNode, int nLevel)
         case TDVIPSNAMESCOL:
         case TICONICCOL:
         {
-            OUStringBuffer sStrBuf(7);
-            sStrBuf.append('#');
             nc = pNode->GetToken().cMathChar.toUInt32(16);
-            sStrBuf.append(Color(ColorTransparency, nc).AsRGBHEXString());
-            OUString ssStr(sStrBuf.makeStringAndClear());
+            OUString ssStr("#" + Color(ColorTransparency, nc).AsRGBHEXString());
             AddAttribute(XML_NAMESPACE_MATH, XML_MATHCOLOR, ssStr);
         }
         break;
diff --git a/starmath/source/parse5.cxx b/starmath/source/parse5.cxx
index d629fd36ddb1..2fc1395ebf8d 100644
--- a/starmath/source/parse5.cxx
+++ b/starmath/source/parse5.cxx
@@ -2662,13 +2662,11 @@ std::unique_ptr<SmExpressionNode> SmParser5::DoError(SmParseError eError)
     DepthProtect aDepthGuard(m_nParseDepth);
 
     // Identify error message
-    OUStringBuffer sStrBuf(128);
-    sStrBuf.append(SmResId(RID_ERR_IDENT));
-    sStrBuf.append(starmathdatabase::getParseErrorDesc(eError));
+    OUString sStrBuf(SmResId(RID_ERR_IDENT) + starmathdatabase::getParseErrorDesc(eError));
 
     // Generate error node
     m_aCurToken.eType = TERROR;
-    m_aCurToken.cMathChar = sStrBuf.makeStringAndClear();
+    m_aCurToken.cMathChar = sStrBuf;
     auto xSNode = std::make_unique<SmExpressionNode>(m_aCurToken);
     SmErrorNode* pErr(new SmErrorNode(m_aCurToken));
     pErr->SetSelection(m_aCurESelection);