[libc-commits] [libc] [libc] Add support for wchar_t in StringConverter. (PR #211867)

[Jeff Bailey via libc-commits]

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@@ -185,22 +211,59 @@ LIBC_INLINE ErrorOr<char8_t> CharacterConverter::pop_utf8() {
   return static_cast<char8_t>(output);
 }
 
+LIBC_INLINE ErrorOr<wchar_t> CharacterConverter::pop_wchar() {
+#if defined(LIBC_TYPES_WCHAR_T_IS_UTF32)
+  ErrorOr<char32_t> Result = pop_utf32();
+  return Result ? ErrorOr<wchar_t>(static_cast<wchar_t>(*Result))
----------------
kaladron wrote:

I'm curious if you could do this and have fewer casts for easier reading:

```c++
LIBC_INLINE ErrorOr<wchar_t> CharacterConverter::pop_wchar() {
#if defined(LIBC_TYPES_WCHAR_T_IS_UTF32)
  ErrorOr<char32_t> res = pop_utf32();
  if (!res)
    return Error(res.error());
  return static_cast<wchar_t>(*res);
#elif defined(LIBC_TYPES_WCHAR_T_IS_UTF16)
  ErrorOr<char16_t> res = pop_utf16();
  if (!res)
    return Error(res.error());
  return static_cast<wchar_t>(*res);
#else
  return Error(-1);
#endif
}
```

(and the one below)

https://github.com/llvm/llvm-project/pull/211867