[PATCH] D132332: [ADT] Clarify llvm::bit_cast implementation comments

[Joe Loser via Phabricator via llvm-commits]

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When reviewing https://reviews.llvm.org/D132330, I noticed a few pre-existing
comments regarding the implementation of `llvm::bit_cast`. These comments are a
bit misleading since `std::bit_cast` is a C++20 standard library thing, not a
C++17 one (otherwise we could use it directly). Clarify that in the comment.
Also, the implementation in standard libraries as mandated by the standard
requires the destination type to be `trivially_copyable`. Remove the comment
that suggests that `llvm::bit_cast` differs from `std::bit_cast` in that manner.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D132332

Files:
  llvm/include/llvm/ADT/bit.h


Index: llvm/include/llvm/ADT/bit.h
===================================================================
--- llvm/include/llvm/ADT/bit.h
+++ llvm/include/llvm/ADT/bit.h
@@ -20,9 +20,8 @@
 
 namespace llvm {
 
-// This implementation of bit_cast is different from the C++17 one in two ways:
-//  - It isn't constexpr because that requires compiler support.
-//  - It requires trivially-constructible To, to avoid UB in the implementation.
+// This implementation of bit_cast is different from the C++20 one.
+// This version isn't constexpr because that requires compiler support.
 template <
     typename To, typename From,
     typename = std::enable_if_t<sizeof(To) == sizeof(From)>


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