Adapted FunctionBase template to accept multiple argument types

* FunctionBase::argument_tuple is a std::tuple specialization type specialized on the argument types passed inside the variadic template argument of FunctionBase
* added tuple Mapper and XObjectValue helper namespaces containing recursive tuple construction and XObjectPtr value extraction logic
* changed all external function implementations accordingly
* this change was implemented to uniformly support different external function argument types than std::string

3 files changed, 97 insertions, 0 deletions

diff --git a/src/support/tuple/mapper.h b/src/support/tuple/mapper.h
new file mode 100644
index 0000000..c95365e
--- /dev/null
+++ b/src/support/tuple/mapper.h
@@ -0,0 +1,62 @@
+#ifndef INPUTXSLT_SRC_SUPPORT_TUPLE_MAPPER_H_
+#define INPUTXSLT_SRC_SUPPORT_TUPLE_MAPPER_H_
+
+#include <xalanc/XPath/XObject.hpp>
+
+#include <tuple>
+#include <type_traits>
+
+#include "common.h"
+#include "xobject_value.h"
+
+namespace InputXSLT {
+
+template <bool Condition>
+using enable_if = typename std::enable_if<Condition, std::size_t>::type;
+
+namespace Mapper {
+	template <
+		typename Target,
+		std::size_t Index = 0,
+		typename Current  = std::tuple<>,
+		enable_if<Index == std::tuple_size<Target>::value> = 0
+	>
+	inline Target construct(
+		const xalan::XPathExecutionContext::XObjectArgVectorType&,
+		Current&& current
+	) {
+		return current;
+	}
+
+	template <
+		typename Target,
+		std::size_t Index = 0,
+		typename Current  = std::tuple<>,
+		enable_if<Index < std::tuple_size<Target>::value> = 0
+	>
+	inline Target construct(
+		const xalan::XPathExecutionContext::XObjectArgVectorType& source,
+		Current&& current = std::tuple<>()
+	) {
+		return construct<
+			Target,
+			Index + 1
+		>(
+			source,
+			std::tuple_cat(
+				current,
+				std::make_tuple(
+					XObjectValue::get<
+						typename std::tuple_element<Index, Target>::type
+					>(
+						source[Index]
+					)
+				)
+			)
+		);
+	}
+};
+
+}
+
+#endif  // INPUTXSLT_SRC_SUPPORT_TUPLE_MAPPER_H_
diff --git a/src/support/tuple/xobject_value.cc b/src/support/tuple/xobject_value.cc
new file mode 100644
index 0000000..3883436
--- /dev/null
+++ b/src/support/tuple/xobject_value.cc
@@ -0,0 +1,18 @@
+#include "xobject_value.h"
+
+#include <string>
+
+#include "support/xalan_string.h"
+
+namespace InputXSLT {
+
+namespace XObjectValue {
+
+template <>
+std::string get<std::string>(const xalan::XObjectPtr& ptr) {
+	return toString(ptr->str());
+}
+
+}
+
+}
diff --git a/src/support/tuple/xobject_value.h b/src/support/tuple/xobject_value.h
new file mode 100644
index 0000000..bb602a4
--- /dev/null
+++ b/src/support/tuple/xobject_value.h
@@ -0,0 +1,17 @@
+#ifndef INPUTXSLT_SRC_SUPPORT_TUPLE_XOBJECT_VALUE_H_
+#define INPUTXSLT_SRC_SUPPORT_TUPLE_XOBJECT_VALUE_H_
+
+#include <xalanc/XPath/XObject.hpp>
+
+#include "common.h"
+
+namespace InputXSLT {
+
+namespace XObjectValue {
+	template <typename Type>
+	Type get(const xalan::XObjectPtr&);
+}
+
+}
+
+#endif  // INPUTXSLT_SRC_SUPPORT_TUPLE_XOBJECT_VALUE_H_