// poor man's iterators are "void *" pointers
wxStringBase::wxStringBase(const void *pStart, const void *pEnd)
{
- InitWith((const wxChar *)pStart, 0,
- (const wxChar *)pEnd - (const wxChar *)pStart);
+ if ( pEnd >= pStart )
+ {
+ InitWith((const wxChar *)pStart, 0,
+ (const wxChar *)pEnd - (const wxChar *)pStart);
+ }
+ else
+ {
+ wxFAIL_MSG( _T("pStart is not before pEnd") );
+ Init();
+ }
}
wxStringBase::wxStringBase(size_type n, wxChar ch)
size_t wxStringBase::find(const wxStringBase& str, size_t nStart) const
{
+ // deal with the special case of empty string first
+ const size_t nLen = length();
+ const size_t nLenOther = str.length();
+
+ if ( !nLenOther )
+ {
+ // empty string is a substring of anything
+ return 0;
+ }
+
+ if ( !nLen )
+ {
+ // the other string is non empty so can't be our substring
+ return npos;
+ }
+
wxASSERT( str.GetStringData()->IsValid() );
- wxASSERT( nStart <= length() );
+ wxASSERT( nStart <= nLen );
+
+ const wxChar * const other = str.c_str();
- //anchor
+ // anchor
const wxChar* p = (const wxChar*)wxTmemchr(c_str() + nStart,
- str.c_str()[0],
- length() - nStart);
+ *other,
+ nLen - nStart);
- if(!p)
+ if ( !p )
return npos;
- while(p - c_str() + str.length() <= length() &&
- wxTmemcmp(p, str.c_str(), str.length()) )
+ while ( p - c_str() + nLenOther <= nLen && wxTmemcmp(p, other, nLenOther) )
{
- //Previosly passed as the first argument to wxTmemchr,
- //but C/C++ standard does not specify evaluation order
- //of arguments to functions -
- //http://embedded.com/showArticle.jhtml?articleID=9900607
- ++p;
-
- //anchor again
- p = (const wxChar*)wxTmemchr(p,
- str.c_str()[0],
- length() - (p - c_str()));
-
- if(!p)
+ p++;
+
+ // anchor again
+ p = (const wxChar*)wxTmemchr(p, *other, nLen - (p - c_str()));
+
+ if ( !p )
return npos;
}
- return (p - c_str() + str.length() <= length()) ? p - c_str() : npos;
+ return p - c_str() + nLenOther <= nLen ? p - c_str() : npos;
}
size_t wxStringBase::find(const wxChar* sz, size_t nStart, size_t n) const