[llvm] [llvm][ADT] Structured bindings for move-only types in `StringMap` (PR #114676)

[Jakub Kuderski via llvm-commits]

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@@ -147,25 +147,33 @@ class StringMapEntry final : public StringMapEntryStorage<ValueTy> {
 };
 
 // Allow structured bindings on StringMapEntry.
+
+template <std::size_t Index, typename ValueTy>
+decltype(auto) get(StringMapEntry<ValueTy> &E) {
+  static_assert(Index == 0 || Index == 1);
+  if constexpr (Index == 0)
+    return E.getKey();
+  if constexpr (Index == 1)
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kuhar wrote:

since this is guarded by the static assert above, we can use `else`

https://github.com/llvm/llvm-project/pull/114676