YT-22473: Enable for-each formatting in known ranges

5a3405e64b730f0056e381af07658d6c2edcb92b

1 files changed, 19 insertions, 0 deletions

diff --git a/library/cpp/yt/string/string.h b/library/cpp/yt/string/string.h
index 8257c1a5ea..b91d1b3805 100644
--- a/library/cpp/yt/string/string.h
+++ b/library/cpp/yt/string/string.h
@@ -27,6 +27,25 @@ struct TDefaultFormatter
     }
 };
 
+//! Bind spec to a formatter.
+//! Used in ranges processing.
+class TSpecBoundFormatter
+{
+public:
+    explicit TSpecBoundFormatter(TStringBuf spec)
+        : Spec_(spec)
+    { }
+
+    template <class T>
+    void operator()(TStringBuilderBase* builder, const T& obj) const
+    {
+        FormatValue(builder, obj, Spec_);
+    }
+
+private:
+    TStringBuf Spec_;
+};
+
 static constexpr TStringBuf DefaultJoinToStringDelimiter = ", ";
 static constexpr TStringBuf DefaultKeyValueDelimiter = ": ";
 static constexpr TStringBuf DefaultRangeEllipsisFormat = "...";