From e7ccc2ead07b5dda0b6ad2ab72cb08a169d10374 Mon Sep 17 00:00:00 2001
From: Orange <orange-cpp@yandex.ru>
Date: Mon, 6 Oct 2025 14:25:52 +0300
Subject: [PATCH] added concept for iterators, reworked interface

---
 include/omath/utility/pattern_scan.hpp | 3 ++-
 source/utility/pattern_scan.cpp        | 9 ++-------
 2 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/include/omath/utility/pattern_scan.hpp b/include/omath/utility/pattern_scan.hpp
index 781c344..d1596a9 100644
--- a/include/omath/utility/pattern_scan.hpp
+++ b/include/omath/utility/pattern_scan.hpp
@@ -36,10 +36,11 @@ namespace omath
 
     public:
         [[nodiscard]]
-        static std::optional<std::span<std::byte>::const_iterator> scan_for_pattern(const std::span<std::byte>& range,
+        static std::span<std::byte>::const_iterator scan_for_pattern(const std::span<std::byte>& range,
                                                                                     const std::string_view& pattern);
 
         template<class IteratorType>
+        requires std::input_or_output_iterator<std::remove_cvref_t<IteratorType>>
         static IteratorType scan_for_pattern(const IteratorType& begin, const IteratorType& end,
                                              const std::string_view& pattern)
         {
diff --git a/source/utility/pattern_scan.cpp b/source/utility/pattern_scan.cpp
index cf19cc3..ff593f7 100644
--- a/source/utility/pattern_scan.cpp
+++ b/source/utility/pattern_scan.cpp
@@ -7,15 +7,10 @@
 namespace omath
 {
 
-    std::optional<std::span<std::byte>::const_iterator>
+    std::span<std::byte>::const_iterator
     PatternScanner::scan_for_pattern(const std::span<std::byte>& range, const std::string_view& pattern)
     {
-        auto result = scan_for_pattern(range.begin(), range.end(), pattern);
-
-        if (result == range.end())
-            return std::nullopt;
-
-        return result;
+        return scan_for_pattern(range.begin(), range.end(), pattern);
     }
     std::expected<std::vector<std::optional<std::byte>>, PatternScanError>
     PatternScanner::parse_pattern(const std::string_view& pattern_string)