ydb/contrib/libs/grpc/patches/20-tstring.patch

--- contrib/libs/grpc/src/core/lib/transport/metadata_batch.h	(3aa9ce0a2551c55167cc7f1129fae1b840fbaa4c)
+++ contrib/libs/grpc/src/core/lib/transport/metadata_batch.h	(26aa0c9a05850d6e4fd9f48970eb77e7f79b8baf)
@@ -661,7 +661,7 @@ class GetStringValueHelper {
     for (const auto& v : *value) {
       if (!backing_->empty()) backing_->push_back(',');
       auto new_segment = Trait::Encode(v);
-      backing_->append(new_segment.begin(), new_segment.end());
+      backing_->append(reinterpret_cast<const char*>(new_segment.begin()), reinterpret_cast<const char*>(new_segment.end()));
     }
     return *backing_;
   }