* Don't copy the input string, a reference will suffice

* Rewrite using switches and iterators   

Patch by Elias Pipping


[[Imported from SVN: r5293]]

common/configparser.cc

@@ -284,20 +284,37 @@ namespace Dune {
 
 }  // end namespace Dune
 
-string ConfigParser::trim(string s)
+
+static inline bool is_space(char c)
 {
-  int i = 0;
-  while ((s[i] == ' ')or (s[i] == '\n') or (s[i] == '\r'))
-    i++;
+  switch (c) {
+  case ' ' :
+  case '\n' :
+  case '\r' :
+    return true;
+  default :
+    return false;
+  }
+}
 
-  s.erase(0,i);
+string ConfigParser::trim(const string& s) const
+{
+  string::const_iterator b = s.begin();
+  string::const_iterator e = s.end();
+
+  for ( ; ; )
+    if (b != e)
+      if (is_space(*b))
+        ++b;
+      else
+        break;
+    else
+      return string();
 
-  i = s.length();
-  while ((s[i-1] == ' ')or (s[i-1] == '\n') or (s[i-1] == '\r'))
-    i--;
+  while (is_space(e[-1]))
+    --e;
 
-  s.erase(i);
-  return s;
+  return string(b, e);
 }
 
 const ConfigParser::KeyVector& ConfigParser::getValueKeys() const

common/configparser.hh

@@ -226,7 +226,7 @@ namespace Dune {
 
     std::map<std::string, std::string> values;
     std::map<std::string, ConfigParser> subs;
-    std::string trim(std::string s);
+    std::string trim(const std::string& s) const;
 
 
   };