j/tree: add templated type conversions

json/tree.cpp

@@ -321,6 +321,54 @@ json::tree::node::as_chars (void) const
 }
 
 
+///////////////////////////////////////////////////////////////////////////////
+namespace json { namespace tree {
+    template <>
+    bool node::as (void) const
+    {
+        return as_bool ();
+    }
+} }
+
+
+//-----------------------------------------------------------------------------
+namespace json { namespace tree {
+    template <>
+    float json::tree::node::as (void) const
+    {
+        return as_float ();
+    }
+} }
+
+
+//-----------------------------------------------------------------------------
+namespace json { namespace tree {
+    template <>
+    double
+    json::tree::node::as (void) const
+    {
+        return as_double ();
+    }
+} }
+
+
+//-----------------------------------------------------------------------------
+#define AS_INTEGRAL(T)                          \
+namespace json { namespace tree {               \
+    template <>                                 \
+    T                                           \
+    node::as (void) const                       \
+    {                                           \
+        return static_cast<T> (as_double ());   \
+    }                                           \
+} }
+
+AS_INTEGRAL(uint8_t)
+AS_INTEGRAL(uint16_t)
+AS_INTEGRAL(uint32_t)
+AS_INTEGRAL(uint64_t)
+
+
 ///////////////////////////////////////////////////////////////////////////////
 // Global operatoers
 bool

json/tree.hpp

@@ -75,6 +75,9 @@ namespace json { namespace tree {
             virtual size_t as_uint   (void) const;
             virtual const char* as_chars (void) const;
 
+            template <typename T>
+            T as (void) const;
+
             virtual bool is_object  (void) const { return false; }
             virtual bool is_array   (void) const { return false; }
             virtual bool is_string  (void) const { return false; }