[libcxx-commits] [libcxx] [RFC][libc++] Fixes valarray proxy type operations. (PR #76528)

[Louis Dionne via libcxx-commits]

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@@ -819,6 +819,19 @@ public:
   _LIBCPP_HIDE_FROM_ABI valarray& operator<<=(const value_type& __x);
   _LIBCPP_HIDE_FROM_ABI valarray& operator>>=(const value_type& __x);
 
+  // The valarray overloads are needed for the types with an implicit
+  // conversion to valarray. For example slice_array.
+  _LIBCPP_HIDE_FROM_ABI valarray& operator*=(const valarray& __v) { return operator*= <valarray>(__v); }
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ldionne wrote:

Instead, I think we should make things like `gslice_array` & friends be `__val_expr`s and give them the necessary indexing operators (via a private name). That would allow for a much more efficient implementation of e.g. `valarray::operator*=` than if we need to create a temporary `valarray` first.

https://github.com/llvm/llvm-project/pull/76528