[libcxx-commits] [libcxx] WIP [libc++][ranges] Add `convertible_to` test case for `enumerate_view` iterator ctor test (PR #212044)

[A. Jiang via libcxx-commits]

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@@ -43,6 +43,7 @@ constexpr void test() {
   };
 
   static_assert(std::is_convertible_v<EnumerateIterator, EnumerateConstIterator>);
+  static_assert(std::convertible_to<EnumerateIterator, EnumerateConstIterator>);
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frederick-vs-ja wrote:

Ah, I see.
- First, I think we should use stronger `convertible_to` for this positive test case.
- Second, we should test some negative cases - in the case that implicit conversion can't be performed for underlying iterators, we should verify that `static_assert(!std::is_convertible_v<...>);`.

https://github.com/llvm/llvm-project/pull/212044