tree 318e6c2804b30edd49a567a411c9f3f3ca700890
parent 4f76523ffef78ba8650c3d4905c6ff90b82dc303
author David Benjamin <davidben@google.com> 1729614944 -0400
committer Boringssl LUCI CQ <boringssl-scoped@luci-project-accounts.iam.gserviceaccount.com> 1729634276 +0000

Standardize on Init vs InitForOverwrite for value vs default initialization

C++ is fun and has two notions of "default" initialization, `new T` and
`new T()`. These are default initialization and value initialization,
respectively.

They are identical except that POD types are uninit when
default-initialized and zero when value-initialized. InplaceVector
picked the safer option by default and called the other one
FooMaybeUninit.  Array is older and uses the less safe one (it's almost
always the one we want; we usually allocate an array to immediately fill
it).

While MaybeUninit does capture what you do with it, it is slightly
ambiguous, as seen in Array's internal implementation: uninitialized
could also mean we haven't gotten around to initialize it at all. I.e.
we need to use a function like std::uninitialized_value_construct_n
instead of normal functions in <algorithm>.

C++20 has std::make_unique and std::make_unique_for_overwrite to capture
the two. This seems as fine a naming convention as any, so switch to it.
Along the way, make the internal bssl::Array default to the safer one.
This lets us remove a couple of memset(0)'s.

Change-Id: I32cede231da051a854e6251e10b87f8e4dd06ee6
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/72268
Reviewed-by: Nick Harper <nharper@chromium.org>
Commit-Queue: David Benjamin <davidben@google.com>