incfs: tolerate either ptrdiff_t or size_t for std::span

The out-of-date std::span in external/libcxx currently uses ptrdiff_t
as the type of size() and the second ctor argument. The C++20 std::span
actually uses size_t for these values instead. Try to accommodate both
versions of std::span until libc++ is upgraded.

Bug: http://b/175635923
Test: treehugger
Change-Id: Idc43f880b6eb21dad79e79fa456847d5865a1ed2

1 files changed, 4 insertions, 1 deletions

diff --git a/services/incremental/BinderIncrementalService.cpp b/services/incremental/BinderIncrementalService.cpp
index 2f031bfe4f3f..45ca5cd84e39 100644
--- a/services/incremental/BinderIncrementalService.cpp
+++ b/services/incremental/BinderIncrementalService.cpp
@@ -216,7 +216,10 @@ static std::span<const uint8_t> toSpan(const ::std::optional<::std::vector<uint8
     if (!content) {
         return {};
     }
-    return {content->data(), (int)content->size()};
+    // TODO(b/175635923): Replace with {content->data(), content->size()} after libc++ is upgraded.
+    // The type of the second std::span ctor param changed from ptrdiff_t to size_t between the old
+    // libc++ and the finalized C++20.
+    return std::span<const uint8_t>(content->data(), content->size());
 }
 
 binder::Status BinderIncrementalService::makeFile(