2 files changed, 18 insertions, 18 deletions

diff --git a/src/support/include_entity_resolver.cc b/src/support/include_entity_resolver.cc
index a00d9e6..68af11a 100644
--- a/src/support/include_entity_resolver.cc
+++ b/src/support/include_entity_resolver.cc
@@ -8,22 +8,24 @@
 
 namespace {
 
-std::pair<bool, std::string> extractFilePath(const std::string& rawPath) {
-	const std::size_t leadingDelimiter = rawPath.find_first_of('[');
-	const std::size_t closingDelimiter = rawPath.find_last_of(']');
+using InputXSLT::XercesStringGuard;
+
+boost::optional<std::string> extractFilePath(const XMLCh* const rawPath) {
+	const std::string filePath         = *XercesStringGuard<char>(rawPath);
+	const std::size_t leadingDelimiter = filePath.find_first_of('[');
+	const std::size_t closingDelimiter = filePath.find_last_of(']');
 
 	if ( leadingDelimiter != std::string::npos &&
 		 closingDelimiter != std::string::npos &&
 		 leadingDelimiter <  closingDelimiter ) {
-		return std::make_pair(
-			true,
-			rawPath.substr(
+		return boost::make_optional(
+			filePath.substr(
 				leadingDelimiter + 1,
 				closingDelimiter - leadingDelimiter - 1
 			)
 		);
 	} else {
-		return std::make_pair(false, std::string());
+		return boost::optional<std::string>();
 	}
 }
 
@@ -51,14 +53,10 @@ xercesc::InputSource* IncludeEntityResolver::resolveEntity(
 	const XMLCh* const systemId
 ) {
 	if ( systemId != nullptr ) {
-		auto filePath = extractFilePath(*XercesStringGuard<char>(systemId));
-
-		if ( filePath.first ) {
-			auto resolvedPath = this->resolve(filePath.second);
-
-			if ( resolvedPath.first ) {
+		if ( auto filePath = extractFilePath(systemId) ) {
+			if ( auto resolvedPath = this->resolve(*filePath) ) {
 				return new xercesc::LocalFileInputSource(
-					*XercesStringGuard<XMLCh>(resolvedPath.second.string())
+					*XercesStringGuard<XMLCh>((*resolvedPath).string())
 				);
 			} else {
 				return nullptr;
@@ -71,7 +69,7 @@ xercesc::InputSource* IncludeEntityResolver::resolveEntity(
 	}
 }
 
-std::pair<bool, boost::filesystem::path> IncludeEntityResolver::resolve(
+boost::optional<boost::filesystem::path> IncludeEntityResolver::resolve(
 	const std::string& filePath) {
 	for ( auto&& context : this->path_ ) {
 		const boost::filesystem::path resolvedPath(
@@ -80,11 +78,11 @@ std::pair<bool, boost::filesystem::path> IncludeEntityResolver::resolve(
 
 		if ( boost::filesystem::exists(resolvedPath) &&
 			 boost::filesystem::is_regular_file(resolvedPath) ) {
-			return std::make_pair(true, resolvedPath);
+			return boost::make_optional(resolvedPath);
 		}
 	}
 
-	return std::make_pair(false, boost::filesystem::path());
+	return boost::optional<boost::filesystem::path>();
 }
 
 }
diff --git a/src/support/include_entity_resolver.h b/src/support/include_entity_resolver.h
index b87e10f..1a3bbc1 100644
--- a/src/support/include_entity_resolver.h
+++ b/src/support/include_entity_resolver.h
@@ -4,6 +4,8 @@
 #include <xercesc/sax/EntityResolver.hpp>
 #include <xercesc/sax/InputSource.hpp>
 
+#include "boost/optional.hpp"
+
 #include <string>
 #include <vector>
 
@@ -20,7 +22,7 @@ class IncludeEntityResolver : public xercesc::EntityResolver {
 			const XMLCh* const
 		);
 
-		std::pair<bool, boost::filesystem::path> resolve(const std::string&);
+		boost::optional<boost::filesystem::path> resolve(const std::string&);
 
 	private:
 		std::vector<FilesystemContext> path_;