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

1 files changed, 6 insertions, 2 deletions

diff --git a/src/function/transform.h b/src/function/transform.h
index fc735f0..2be8925 100644
--- a/src/function/transform.h
+++ b/src/function/transform.h
@@ -5,7 +5,11 @@
 
 namespace InputXSLT {
 
-class FunctionTransform : public FunctionBase<FunctionTransform, 2> {
+class FunctionTransform : public FunctionBase<
+	FunctionTransform,
+	std::string,
+	std::string
+> {
 	public:
 		using FunctionBase::FunctionBase;
 
@@ -14,7 +18,7 @@ class FunctionTransform : public FunctionBase<FunctionTransform, 2> {
 
 		xercesc::DOMDocument* constructDocument(
 			const FilesystemContext&,
-			const FunctionBase::argument_array&
+			const FunctionBase::argument_tuple&
 		);
 
 };