make the paramtertree parser recognize true,yes,false,no as nool values

[[Imported from SVN: r6151]]

dune/common/parametertree.cc

@@ -7,6 +7,7 @@
 #include <sstream>
 #include <fstream>
 #include <set>
+#include <algorithm>
 
 #include <dune/common/exceptions.hh>
 #include <dune/common/parametertree.hh>
@@ -14,6 +15,15 @@
 using namespace Dune;
 using namespace std;
 
+namespace {
+  struct ToLower {
+    int operator()(int c)
+    {
+      return std::tolower(c);
+    }
+  };
+}
+
 ParameterTree::ParameterTree()
 {}
 
@@ -187,6 +197,13 @@ bool ParameterTree::get(const string& key, bool defaultValue) const
     stream << 0;
 
   string ret = get(key, stream.str());
+  std::transform(ret.begin(), ret.end(), ret.begin(), ToLower());
+
+  if (ret == "yes" || ret == "true")
+    return true;
+
+  if (ret == "no" || ret == "false")
+    return true;
 
   return (atoi(ret.c_str()) !=0 );
 }
@@ -225,8 +242,19 @@ namespace Dune {
   bool ParameterTree::get<bool>(const string& key) const
   {
     if (hasKey(key))
-      return (std::atoi((*this)[key].c_str()) !=0 );
+    {
+
+      string ret = (*this)[key];
+      std::transform(ret.begin(), ret.end(), ret.begin(), ToLower());
+
+      if (ret == "yes" || ret == "true")
+        return true;
+
+      if (ret == "no" || ret == "false")
+        return true;
 
+      return (std::atoi(ret.c_str()) !=0 );
+    }
     DUNE_THROW(RangeError, "Key '" << key << "' not found in parameter file!");
   }