intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 42 insertions, 0 deletions

diff --git a/library/cpp/digest/lower_case/lciter.h b/library/cpp/digest/lower_case/lciter.h
new file mode 100644
index 0000000000..9538e57932
--- /dev/null
+++ b/library/cpp/digest/lower_case/lciter.h
@@ -0,0 +1,42 @@
+#pragma once
+
+#include <util/generic/typetraits.h>
+#include <util/string/ascii.h>
+
+#include <iterator>
+
+template <class T>
+struct TLowerCaseIterator: public std::iterator<std::input_iterator_tag, T> {
+    using TNonConst = std::remove_const_t<T>;
+
+    inline TLowerCaseIterator(T* c)
+        : C(c)
+    {
+    }
+
+    inline TLowerCaseIterator& operator++() noexcept {
+        ++C;
+
+        return *this;
+    }
+
+    inline TLowerCaseIterator operator++(int) noexcept {
+        return C++;
+    }
+
+    inline TNonConst operator*() const noexcept {
+        return AsciiToLower(*C);
+    }
+
+    T* C;
+};
+
+template <class T>
+inline bool operator==(const TLowerCaseIterator<T>& l, const TLowerCaseIterator<T>& r) noexcept {
+    return l.C == r.C;
+}
+
+template <class T>
+inline bool operator!=(const TLowerCaseIterator<T>& l, const TLowerCaseIterator<T>& r) noexcept {
+    return !(l == r);
+}