From a9998984ed6d582c6b865ad1e7fa7b035a778c01 Mon Sep 17 00:00:00 2001
From: randomdan <randomdan@localhost>
Date: Fri, 18 Mar 2011 16:11:17 +0000
Subject: Add native conversion of VariableTypes to int32_t Templatize the
 numeric conversions for VariableTypes

---
 project2/variableConvert.cpp | 64 +++++++++++++++-----------------------------
 project2/variables.h         |  1 +
 2 files changed, 22 insertions(+), 43 deletions(-)

diff --git a/project2/variableConvert.cpp b/project2/variableConvert.cpp
index 8797ef7..ea6ddef 100644
--- a/project2/variableConvert.cpp
+++ b/project2/variableConvert.cpp
@@ -145,56 +145,30 @@ class ConvertVisitorUCharStar : public boost::static_visitor<const unsigned char
 	private:
 		const VariableType * var;
 };
-// Convert to int64_t
-class ConvertVisitorInt : public boost::static_visitor<int64_t> {
+// Convert to generic type
+template <typename DestType>
+class ConvertVisitor : public boost::static_visitor<DestType> {
 	public:
-		ConvertVisitorInt(const VariableType * v) : var(v) {
+		ConvertVisitor(const VariableType * v) : var(v) {
 		}
-		int64_t operator()(const Glib::ustring & r) const {
-			return boost::lexical_cast<int64_t>(r);
+		DestType operator()(const Glib::ustring & r) const {
+			return boost::lexical_cast<DestType>(r);
 		}
-		int64_t operator()(const boost::shared_ptr<const Glib::ustring> & r) const {
-			return boost::lexical_cast<int64_t>(*r);
+		DestType operator()(const boost::shared_ptr<const Glib::ustring> & r) const {
+			return boost::lexical_cast<DestType>(*r);
 		}
-		int64_t operator()(const boost::posix_time::ptime &) const {
-			throw InvalidConversionTo("Integer");
+		DestType operator()(const boost::posix_time::ptime &) const {
+			throw InvalidConversionTo(typeid(DestType).name());
 		}
-		int64_t operator()(const boost::shared_ptr<const boost::posix_time::ptime> &) const {
-			throw InvalidConversionTo("Integer");
+		DestType operator()(const boost::shared_ptr<const boost::posix_time::ptime> &) const {
+			throw InvalidConversionTo(typeid(DestType).name());
 		}
-		int64_t operator()(const Null &) const {
+		DestType operator()(const Null &) const {
 			throw NullVariable();
 		}
 		template <typename T>
-		int64_t operator()(const T & r) const {
-			return boost::numeric_cast<int64_t>(r);
-		}
-	private:
-		const VariableType * var;
-};
-// Convert to double
-class ConvertVisitorDouble : public boost::static_visitor<double> {
-	public:
-		ConvertVisitorDouble(const VariableType * v) : var(v) {
-		}
-		double operator()(const Glib::ustring & r) const {
-			return boost::lexical_cast<double>(r);
-		}
-		double operator()(const boost::shared_ptr<const Glib::ustring> & r) const {
-			return boost::lexical_cast<double>(*r);
-		}
-		double operator()(const boost::posix_time::ptime &) const {
-			throw InvalidConversionTo("Floating point");
-		}
-		double operator()(const boost::shared_ptr<const boost::posix_time::ptime> &) const {
-			throw InvalidConversionTo("Floating point");
-		}
-		double operator()(const Null &) const {
-			throw NullVariable();
-		}
-		template <typename T>
-		double operator()(const T & r) const {
-			return boost::numeric_cast<double>(r);
+		DestType operator()(const T & r) const {
+			return boost::numeric_cast<DestType>(r);
 		}
 	private:
 		const VariableType * var;
@@ -242,13 +216,17 @@ VariableType::operator const unsigned char *() const
 {
 	return boost::apply_visitor(ConvertVisitorUCharStar(this), *this);
 }
+VariableType::operator int32_t() const
+{
+	return boost::apply_visitor(ConvertVisitor<int32_t>(this), *this);
+}
 VariableType::operator int64_t() const
 {
-	return boost::apply_visitor(ConvertVisitorInt(this), *this);
+	return boost::apply_visitor(ConvertVisitor<int64_t>(this), *this);
 }
 VariableType::operator double() const
 {
-	return boost::apply_visitor(ConvertVisitorDouble(this), *this);
+	return boost::apply_visitor(ConvertVisitor<double>(this), *this);
 }
 VariableType::operator const boost::posix_time::ptime &() const
 {
diff --git a/project2/variables.h b/project2/variables.h
index 863355c..5e29547 100644
--- a/project2/variables.h
+++ b/project2/variables.h
@@ -50,6 +50,7 @@ class VariableType : public _VT {
 		operator const char *() const;
 		operator const unsigned char *() const;
 		operator int64_t() const;
+		operator int32_t() const;
 		operator double() const;
 		operator const boost::posix_time::ptime &() const;
 
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