moved case insensitive comparison utility functions into CString

from CHTTPProtocol.

base/CString.cpp

@@ -0,0 +1,47 @@
+#include "CString.h"
+#include <ctype.h>
+#include <algorithm>
+
+//
+// CStringUtil::CaselessCmp
+//
+
+bool					CStringUtil::CaselessCmp::cmpEqual(
+								const CString::value_type& a,
+								const CString::value_type& b)
+{
+	// FIXME -- use std::tolower
+	return tolower(a) == tolower(b);
+}
+
+bool					CStringUtil::CaselessCmp::cmpLess(
+								const CString::value_type& a,
+								const CString::value_type& b)
+{
+	// FIXME -- use std::tolower
+	return tolower(a) < tolower(b);
+}
+
+bool					CStringUtil::CaselessCmp::less(
+								const CString& a,
+								const CString& b)
+{
+	return std::lexicographical_compare(
+								a.begin(), a.end(),
+								b.begin(), b.end(),
+								&CStringUtil::CaselessCmp::cmpLess);
+}
+
+bool					CStringUtil::CaselessCmp::equal(
+								const CString& a,
+								const CString& b)
+{
+	return !(less(a, b) || less(b, a));
+}
+
+bool					CStringUtil::CaselessCmp::operator()(
+								const CString& a,
+								const CString& b) const
+{
+	return less(a, b);
+}