[core] Replace const string & with string_view in TClassEdit::CleanType

Author: silverweed

core/foundation/inc/TClassEdit.h

@@ -202,7 +202,7 @@ namespace TClassEdit {
 
    void        Init(TClassEdit::TInterpreterLookupHelper *helper);
 
-   std::string CleanType (const char *typeDesc,int mode = 0,const char **tail = nullptr);
+   std::string CleanType (std::string_view typeDesc,int mode = 0,const char **tail = nullptr);
    inline bool IsArtificial(std::string_view name) { return name.find('@') != name.npos; }
    bool        IsDefAlloc(const char *alloc, const char *classname);
    bool        IsDefAlloc(const char *alloc, const char *keyclassname, const char *valueclassname);

core/foundation/src/TClassEdit.cxx

@@ -1286,7 +1286,7 @@ int TClassEdit::GetSplit(const char *type, vector<string>& output, int &nestedLo
 ///      CleanType(" A<B, C< D, E> > *,F,G>") returns "A<B,C<D,E> >*"
 ////////////////////////////////////////////////////////////////////////////
 
-string TClassEdit::CleanType(const char *typeDesc, int mode, const char **tail)
+string TClassEdit::CleanType(std::string_view typeDesc, int mode, const char **tail)
 {
    constexpr static std::array<const char *, 3> remove{"class", "const", "volatile"};
    constexpr static auto lengths = []() constexpr {
@@ -1297,12 +1297,13 @@ string TClassEdit::CleanType(const char *typeDesc, int mode, const char **tail)
    }();
 
    string result;
-   result.reserve(strlen(typeDesc)*2);
+   result.reserve(typeDesc.size()*2);
    int kbl=1;
    std::vector<char> parensStack;
-   const char* c;
+   const char* c = nullptr;
 
-   for(c=typeDesc;*c;c++) {
+   for(auto i = 0u; i < typeDesc.size(); ++i) {
+      c = typeDesc.data() + i;
       if (std::isspace(c[0])) {
          if (kbl)       continue;
          if (!isalnum(c[ 1]) && c[ 1] !='_')    continue;
@@ -1328,7 +1329,7 @@ string TClassEdit::CleanType(const char *typeDesc, int mode, const char **tail)
             // make sure that the 'keyword' is not part of a longer indentifier
             if (isalnum(c[rlen]) || c[rlen]=='_' ||  c[rlen]=='$') continue;
 
-            c+=rlen-1; done = 1; break;
+            c+=rlen-1; i+=rlen-1; done = 1; break;
          }
          if (done) continue;
       }

tree/ntuple/src/RFieldUtils.cxx

@@ -463,7 +463,7 @@ std::string GetRenormalizedDemangledTypeName(std::string_view demangledName, boo
 std::string ROOT::Internal::GetCanonicalTypePrefix(std::string_view typeName)
 {
    // Remove outer cv qualifiers and extra white spaces
-   const std::string cleanedType = TClassEdit::CleanType(std::string(typeName).c_str(), /*mode=*/1);
+   const std::string cleanedType = TClassEdit::CleanType(typeName, /*mode=*/1);
 
    // Can happen when called from RFieldBase::Create() and is caught there
    if (cleanedType.empty())