Switch TString and TStringBase to std::reverse_iterator

At the time an attempt to use e. g. `std::find_if` with `TString::rbegin()` / `TString::rend()` does not compile against `-DUSE_STL_SYSTEM` / modern libstdc++.

3 files changed, 9 insertions, 56 deletions

diff --git a/util/generic/strbase.h b/util/generic/strbase.h
index 08824943b1..86e5c0f2f2 100644
--- a/util/generic/strbase.h
+++ b/util/generic/strbase.h
@@ -51,60 +51,7 @@ public:
     using const_iterator = const TCharType*;
     using const_reference = const TCharType&;
 
-    template <typename TBase>
-    struct TReverseIteratorBase {
-        constexpr TReverseIteratorBase() noexcept = default;
-        explicit constexpr TReverseIteratorBase(TBase p)
-            : P_(p)
-        {
-        }
-
-        TReverseIteratorBase operator++() noexcept {
-            --P_;
-            return *this;
-        }
-
-        TReverseIteratorBase operator++(int) noexcept {
-            TReverseIteratorBase old(*this);
-            --P_;
-            return old;
-        }
-
-        TReverseIteratorBase& operator--() noexcept {
-            ++P_;
-            return *this;
-        }
-
-        TReverseIteratorBase operator--(int) noexcept {
-            TReverseIteratorBase old(*this);
-            ++P_;
-            return old;
-        }
-
-        constexpr auto operator*() const noexcept -> std::remove_pointer_t<TBase>& {
-            return *TBase(*this);
-        }
-
-        explicit constexpr operator TBase() const noexcept {
-            return TBase(P_ - 1);
-        }
-
-        constexpr auto operator-(const TReverseIteratorBase o) const noexcept {
-            return o.P_ - P_;
-        }
-
-        constexpr bool operator==(const TReverseIteratorBase o) const noexcept {
-            return P_ == o.P_;
-        }
-
-        constexpr bool operator!=(const TReverseIteratorBase o) const noexcept {
-            return !(*this == o);
-        }
-
-    private:
-        TBase P_ = nullptr;
-    };
-    using const_reverse_iterator = TReverseIteratorBase<const_iterator>;
+    using const_reverse_iterator = std::reverse_iterator<const_iterator>;
 
     static constexpr size_t StrLen(const TCharType* s) noexcept {
         if (Y_LIKELY(s)) {
diff --git a/util/generic/string.h b/util/generic/string.h
index 5f56954481..fd3c771749 100644
--- a/util/generic/string.h
+++ b/util/generic/string.h
@@ -175,7 +175,7 @@ public:
     using traits_type = TTraits;
 
     using iterator = TCharType*;
-    using reverse_iterator = typename TBase::template TReverseIteratorBase<iterator>;
+    using reverse_iterator = std::reverse_iterator<iterator>;
     using typename TBase::const_iterator;
     using typename TBase::const_reference;
     using typename TBase::const_reverse_iterator;
diff --git a/util/generic/string_ut.h b/util/generic/string_ut.h
index 44bb10bdeb..3a91f61dd1 100644
--- a/util/generic/string_ut.h
+++ b/util/generic/string_ut.h
@@ -906,7 +906,7 @@ public:
         s2.assign(Data._0123456(), 2, 2);
         UNIT_ASSERT(s2 == Data._23());
 
-        //s2.reserve();
+        // s2.reserve();
 
         TStringType s5(Data.abcde());
         s5.clear();
@@ -1152,5 +1152,11 @@ public:
 
         *ritBegin = (ui8)'e';
         UNIT_ASSERT_VALUES_EQUAL(*ritBegin, (ui8)'e');
+
+        str = chars;
+        auto it = std::find_if(
+            str.rbegin(), str.rend(),
+            [](char_type c) { return c == 'o'; });
+        UNIT_ASSERT_EQUAL(it, str.rbegin());
     }
 };