Index: boost/spirit/home/support/utree/detail/utree_detail2.hpp
===================================================================
--- boost/spirit/home/support/utree/detail/utree_detail2.hpp	(revision 84392)
+++ boost/spirit/home/support/utree/detail/utree_detail2.hpp	(working copy)
@@ -469,6 +469,9 @@
                 case type::int_type:
                     return f(x.i);
 
+                case type::float_type:
+                    return f(x.f);
+
                 case type::double_type:
                     return f(x.d);
 
Index: boost/spirit/home/support/utree/utree.hpp
===================================================================
--- boost/spirit/home/support/utree/utree.hpp	(revision 84392)
+++ boost/spirit/home/support/utree/utree.hpp	(working copy)
@@ -80,6 +80,7 @@
             // numeric atoms
             bool_type,          // An utree holding a boolean value
             int_type,           // An utree holding a integer (int) value
+            float_type,         // An utree holding a floating point (float) value
             double_type,        // An utree holding a floating point (double) value
 
             // text atoms (utf8)
@@ -108,6 +109,7 @@
             case utree_type::function_type: { out << "function"; break; }
             case utree_type::bool_type: { out << "bool"; break; }
             case utree_type::int_type: { out << "int"; break; }
+            case utree_type::float_type: { out << "float"; break; }
             case utree_type::double_type: { out << "double"; break; }
             case utree_type::string_type: { out << "string"; break; }
             case utree_type::string_range_type: { out << "string_range"; break; }
@@ -398,6 +400,11 @@
         reference operator=(unsigned int);
         reference operator=(int);
 
+        // This initializes a `float_type` node, which can hold arbitrary 
+        // floating point (float) values.
+        utree(float);
+        reference operator=(float);
+
         // This initializes a `double_type` node, which can hold arbitrary 
         // floating point (double) values.
         utree(double);
@@ -598,6 +605,7 @@
             detail::void_ptr v;
             bool b;
             int i;
+            float f;
             double d;
             utree* p;
             function_base* pf;
Index: boost/spirit/home/support/utree/utree_traits.hpp
===================================================================
--- boost/spirit/home/support/utree/utree_traits.hpp	(revision 84392)
+++ boost/spirit/home/support/utree/utree_traits.hpp	(working copy)
@@ -901,6 +901,18 @@
     };
 
     template <>
+    struct compute_compatible_component_variant<utree, float>
+      : mpl::true_
+    {
+        typedef float compatible_type;
+
+        static bool is_compatible(int d)
+        {
+            return d == utree_type::float_type;
+        }
+    };
+
+    template <>
     struct compute_compatible_component_variant<utree, double>
       : mpl::true_
     {
@@ -1122,6 +1134,18 @@
     };
 
     template <>
+    struct extract_from_container<utree, float>
+    {
+        typedef float type;
+
+        template <typename Context>
+        static type call(utree const& t, Context&)
+        {
+            return detail::get_or_deref<float>(t);
+        }
+    };
+
+    template <>
     struct extract_from_container<utree, double>
     {
         typedef double type;
@@ -1219,6 +1243,17 @@
     };
 
     template <>
+    struct transform_attribute<utree const, float, karma::domain>
+    {
+        typedef float type;
+
+        static type pre(utree const& t)
+        {
+            return detail::get_or_deref<float>(t);
+        }
+    };
+
+    template <>
     struct transform_attribute<utree const, double, karma::domain>
     {
         typedef double type;