Refactoring: remove implicit conversion from QCString to const char *

This commit changes the following in relation to string use
- The implicit convert from 'QCString' to 'const char *' is removed
- Strings parameters use 'const QCString &' as much as possible in favor
  over 'const char *'
- 'if (s)' where s is a QCString has been replaced by 'if(!s.isEmpty())'
- data() now always returns a valid C-string and not a 0-pointer.
- when passing a string 's' to printf and related functions 'qPrint(s)' is
  used instead of 's.data()'
- for empty string arguments 'QCString()' is used instead of '0'
- The copy() operation has been removed
- Where possible 'qstrcmp(a,b)==0' has been replaces by 'a==b' and
  'qstrcmp(a,b)<0' has been replaced by 'a<b'
- Parameters of string type that were default initialized with '= 0' are
  no initialized with '= QCString()'

1 files changed, 2 insertions, 2 deletions

diff --git a/src/docvisitor.cpp b/src/docvisitor.cpp
index 5356faf..506c9f8 100644
--- a/src/docvisitor.cpp
+++ b/src/docvisitor.cpp
@@ -38,9 +38,9 @@ DocVisitor::~DocVisitor()
 {
 }
 
-CodeParserInterface &DocVisitor::getCodeParser(const char *extension)
+CodeParserInterface &DocVisitor::getCodeParser(const QCString &extension)
 {
-  std::string ext(extension?extension:"");
+  std::string ext = extension.str();
   // for each extension we create a code parser once per visitor, so that
   // the context of the same parser object is reused throughout multiple passes for instance
   // for code fragments shown via dontinclude.