#2439 typed a range-for variable when the loop names its type. A loop
over `auto` elements names none, so receiver inference kept scanning as
for an `auto` local with an unreadable initializer: it reached an earlier
declaration of the same name, often another variable's, or fell through
to the guess by the receiver's name. facebook/rocksdb's db_impl_write.cc
loops `for (auto cfd : cfds)` over a `const autovector<ColumnFamilyData*>&`.
The loop's range is now read from its header and typed as written,
template arguments and all, since the index keeps only a return type's
last name:
- a name the calling function declares, or a data member of its class
read from the class's own lines (`versions_` from db_impl_write.cc);
- an `auto` local's initializer;
- `*x`, `x.m`, `x->m`, `this`, and calls whose declaration writes their
return type, free or on the object's class (own or inherited);
- aliases followed with their template arguments (cppAliasedTypeWritten);
- the element: a standard or abseil sequence container's first template
argument, protobuf's RepeatedPtrField and rocksdb's autovector's, or what
a project class's begin() returns, dereferenced (ColumnFamilySet's
iterator's operator* gives ColumnFamilyData*). Nullability annotations
are dropped.
The element goes through the same declaration record as any declared
receiver, so the typed path, #2413's gate for a standard-library element
and #2440's held-type lookup for `->` on a smart-pointer element apply
unchanged. Classes are looked up with #2440's cppClassWritten, methods
through its cppMethodOf, and matchCppHeldTypeCall now reads its held type
through the shared cppStdHeldType.
A/B on main 8a5ba3d0, site-keyed: leveldb identical; fmt +1 / 3
retargeted; rocksdb -68 / +173 / 104 retargeted / 231 confidence only;
protobuf -13 / +25 / 7 / 59. Every removal and retarget was a wrong
guess; 4 of rocksdb's additions reach MemTableRep::Iterator through the
typed path's last-name lookup, as a declared `Iterator* it` does on main.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Colby Mchenry