template CharacterConverter size method

Author: uzairnawaz

libc/src/__support/wchar/character_converter.cpp

@@ -132,12 +132,6 @@ ErrorOr<char32_t> CharacterConverter::pop_utf32() {
   return utf32;
 }
 
-size_t CharacterConverter::sizeAsUTF32() {
-  return 1; // a single utf-32 value can fit an entire character
-}
-
-size_t CharacterConverter::sizeAsUTF8() { return state->total_bytes; }
-
 ErrorOr<char8_t> CharacterConverter::pop_utf8() {
   if (isEmpty())
     return Error(-1);

libc/src/__support/wchar/character_converter.h

@@ -32,8 +32,12 @@ class CharacterConverter {
   bool isEmpty();
   bool isValidState();
 
-  size_t sizeAsUTF32();
-  size_t sizeAsUTF8();
+  template <typename CharType> size_t sizeAs() {
+    if constexpr (cpp::is_same_v<CharType, char8_t>)
+      return state->total_bytes;
+    else        // char32_t
+      return 1; // every character fits in a single char32_t
+  }
 
   int push(char8_t utf8_byte);
   int push(char32_t utf32);

libc/src/__support/wchar/string_converter.h

@@ -63,13 +63,7 @@ template <typename T> class StringConverter {
       if (!src_elements_read.has_value())
         return Error(src_elements_read.error());
 
-      size_t size;
-      if constexpr (cpp::is_same_v<CharType, char8_t>)
-        size = cr.sizeAsUTF8();
-      else
-        size = cr.sizeAsUTF32();
-
-      if (size > num_to_write) {
+      if (cr.sizeAs<CharType>() > num_to_write) {
         cr.clear();
         return Error(-1);
       }