double value support

include/mstch/mstch.hpp

@@ -84,7 +84,7 @@ class lambda {
 };
 
 using node = boost::make_recursive_variant<
-    std::nullptr_t, std::string, int, bool, lambda,
+    std::nullptr_t, std::string, int, double, bool, lambda,
     std::shared_ptr<internal::object_t<boost::recursive_variant_>>,
     std::map<const std::string, boost::recursive_variant_>,
     std::vector<boost::recursive_variant_>>::type;

src/visitor/is_node_empty.hpp

@@ -24,6 +24,11 @@ inline bool is_node_empty::operator()(const int& value) const {
   return value == 0;
 }
 
+template<>
+inline bool is_node_empty::operator()(const double& value) const {
+  return value == 0;
+}
+
 template<>
 inline bool is_node_empty::operator()(const bool& value) const {
   return !value;

src/visitor/render_node.hpp

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <sstream>
 #include <boost/variant/static_visitor.hpp>
 
 #include "mstch/mstch.hpp"
@@ -27,6 +28,13 @@ inline std::string render_node::operator()(const int& value) const {
   return std::to_string(value);
 }
 
+template<>
+inline std::string render_node::operator()(const double& value) const {
+  std::stringstream ss;
+  ss << value;
+  return ss.str();
+}
+
 template<>
 inline std::string render_node::operator()(const bool& value) const {
   return value?"true":"false";

test/data/dot_notation.hpp

@@ -17,7 +17,7 @@ public:
   }
 
   mstch::node vat() {
-    return static_cast<int>(m_value * 0.2);
+    return m_value * 0.2;
   }
 
   mstch::node currency() {

test/data/partial_view.hpp

@@ -1,6 +1,7 @@
 class partial_view: public mstch::object {
 private:
   int m_value;
+
 public:
     partial_view(): m_value{10000} {
     register_methods(this, {
@@ -30,7 +31,7 @@ public:
   }
 
   mstch::node taxed_value() {
-    return static_cast<int>(m_value - (m_value * 0.4));
+    return m_value - (m_value * 0.4);
   }
 
   mstch::node in_ca() {

test/data/simple.hpp

@@ -21,7 +21,7 @@ public:
   }
 
   mstch::node taxed_value() {
-    return static_cast<int>(m_value - (m_value * 0.4));
+    return m_value - (m_value * 0.4);
   }
 
   mstch::node in_ca() {