utils: Satisfy LegacyInputIterator with StringSplitter::iterator

The StringSplitter::iterator is used with the utils::split() function to
iterate over components of a split string. Add the necessary member
types expected by std::iterator_trait in order to satisfy the
LegacyInputIterator requirement and make the iterator usable in
constructors for various containers.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/include/libcamera/base/utils.h b/include/libcamera/base/utils.h
index 889bb4a2..ed88b716 100644
--- a/include/libcamera/base/utils.h
+++ b/include/libcamera/base/utils.h
@@ -170,6 +170,12 @@ public:
 	class iterator
 	{
 	public:
+		using difference_type = std::size_t;
+		using value_type = std::string;
+		using pointer = value_type *;
+		using reference = value_type &;
+		using iterator_category = std::input_iterator_tag;
+
 		iterator(const StringSplitter *ss, std::string::size_type pos);
 
 		iterator &operator++();