[clang] [libcxx] [llvm] [Clang] Add warnings when mixing different charN_t types (PR #138708)

[via cfe-commits]

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@@ -34,6 +34,6 @@ int main(int, char**) {
   assert(from_next - from == 9);
   assert(to_next - to == 9);
   for (unsigned i = 0; i < 9; ++i)
-    assert(to[i] == from[i]);
+    assert(static_cast<char32_t>(to[i]) == static_cast<char32_t>(from[i]));
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cor3ntin wrote:

I removed the redundant cast

https://github.com/llvm/llvm-project/pull/138708