Fixed #6716 (Performance: Alternative String Representation in Match Compiler)

lib/matchcompiler.h

@@ -0,0 +1,75 @@
+/*
+ * Cppcheck - A tool for static C/C++ code analysis
+ * Copyright (C) 2007-2015 Daniel Marjamäki and Cppcheck team.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+//---------------------------------------------------------------------------
+#ifndef matchcompilerH
+#define matchcompilerH
+
+#include <string>
+
+namespace MatchCompiler {
+
+    template <unsigned int n>
+    class ConstString {
+    public:
+        typedef const char(&StringRef)[n];
+        explicit ConstString(StringRef s)
+            :_s(s) {
+        }
+
+        operator StringRef() const {
+            return _s;
+        }
+
+    private:
+        StringRef _s;
+    };
+
+    template <unsigned int n>
+    inline bool equalN(const char s1[], const char s2[])
+    {
+        return (*s1 == *s2) && equalN<n-1>(s1+1, s2+1);
+    }
+
+    template <>
+    inline bool equalN<0>(const char [], const char [])
+    {
+        return true;
+    }
+
+    template <unsigned int n>
+    inline bool operator==(const std::string & s1, ConstString<n> const & s2)
+    {
+        return equalN<n>(s1.c_str(), s2);
+    }
+
+    template <unsigned int n>
+    inline bool operator!=(const std::string & s1, ConstString<n> const & s2)
+    {
+        return !operator==(s1,s2);
+    }
+
+    template <unsigned int n>
+    inline ConstString<n> makeConstString(const char(&s)[n])
+    {
+        return ConstString<n>(s);
+    }
+}
+
+#endif // matchcompilerH
+