[libc-commits] [libc] [libc] Add UTF-16 support in CharacterConverter [1/6] (PR #230434)

[Michael Jones via libc-commits]

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@@ -127,6 +194,57 @@ LIBC_INLINE int CharacterConverter::push(char8_t utf8_byte) {
   return EILSEQ;
 }
 
+LIBC_INLINE int CharacterConverter::push(char16_t utf16) {
+  // Checking for high surrogate if first push
+  if (isEmpty()) {
+    bool is_surrogate = (utf16 & 0xF800) == 0xD800;
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michaelrj-google wrote:

here and below, we want to avoid "Magic Numbers" which are usually integer constants used in the code with no explanation or context. In this line both `0xF800` and `0xD800` are magic numbers. Generally the easiest way to avoid magic numbers is to define a `const` or `constexpr` value and give it a descriptive name. This also makes it easier to reuse the value elsewhere in the code. For these I might call them `UTF16_SURROGATE_START` and `UTF16_SURROGATE_END` or similar.

https://github.com/llvm/llvm-project/pull/230434