Update ex9_44.cpp

ch09/ex9_44.cpp

@@ -6,29 +6,32 @@
 //
 //  @Brief  Rewrite the previous function using an index and replace.
 //  @See    9.43
+//
+//  Refactored by Yue Wang Oct, 2015
+//
 
 #include <iostream>
 #include <string>
 
-using std::cout; using std::endl; using std::string;
+using std::cout; 
+using std::endl;
+using std::string;
 
-void func(string &s, string const& oldVal, string const& newVal)
+auto replace_with(string &s, string const& oldVal, string const& newVal)
 {
-    for (size_t pos = 0; pos <= s.size() - oldVal.size();) {
-        if (s[pos] == oldVal[0] && s.substr(pos, oldVal.size()) == oldVal) {
-            s.replace(pos, oldVal.size(), newVal);
+    for (size_t pos = 0; pos <= s.size() - oldVal.size();)
+        if (s[pos] == oldVal[0] && s.substr(pos, oldVal.size()) == oldVal)
+            s.replace(pos, oldVal.size(), newVal),
             pos += newVal.size();
-        }
         else
             ++pos;
-    }
 }
 
 int main()
 {
     string str{ "To drive straight thru is a foolish, tho courageous act." };
-    func(str, "tho", "though");
-    func(str, "thru", "through");
+    replace_with(str, "tho", "though");
+    replace_with(str, "thru", "through");
     cout << str << endl;
     return 0;
 }