feat: Implement Rust-side const ExternalOneByteStringResource subclass

src/string.rs

@@ -122,46 +122,34 @@ type OneByteConstIsCacheable = extern "C" fn(&'static OneByteConst) -> bool;
 type OneByteConstData = extern "C" fn(&'static OneByteConst) -> *const char;
 type OneByteConstLength = extern "C" fn(&'static OneByteConst) -> usize;
 
-type OneByteConstVtable = (
- // typeinfo / metadata pointer
- *const (),
- // base offset
- usize,
- // Destructor & Delete
- OneByteConstNoOp,
- OneByteConstNoOp,
- // IsCacheable
- OneByteConstIsCacheable,
- // Dispose
- OneByteConstNoOp,
- // Lock
- OneByteConstNoOp,
- // Unlock
- OneByteConstNoOp,
- // Data
- OneByteConstData,
- // Length
- OneByteConstLength,
- // UpdateDataCache
- OneByteConstNoOp,
- // CheckCachedDataInvariants
- OneByteConstNoOp,
-);
-
-const ONE_BYTE_CONST_VTABLE: OneByteConstVtable = (
- std::ptr::null(),
- 0,
- one_byte_const_no_op,
- one_byte_const_no_op,
- one_byte_const_is_cacheable,
- one_byte_const_no_op,
- one_byte_const_no_op,
- one_byte_const_no_op,
- one_byte_const_data,
- one_byte_const_length,
- one_byte_const_no_op,
- one_byte_const_no_op,
-);
+#[repr(C)]
+struct OneByteConstVtable {
+ _typeinfo: *const (),
+ _base_offset: usize,
+ delete1: OneByteConstNoOp,
+ #[cfg(not(target_family = "windows"))]
+ delete2: OneByteConstNoOp,
+ is_cacheable: OneByteConstIsCacheable,
+ dispose: OneByteConstNoOp,
+ lock: OneByteConstNoOp,
+ unlock: OneByteConstNoOp,
+ data: OneByteConstData,
+ length: OneByteConstLength,
+}
+
+const ONE_BYTE_CONST_VTABLE: OneByteConstVtable = OneByteConstVtable {
+ _typeinfo: std::ptr::null(),
+ _base_offset: 0,
+ delete1: one_byte_const_no_op,
+ #[cfg(not(target_family = "windows"))]
+ delete2: one_byte_const_no_op,
+ is_cacheable: one_byte_const_is_cacheable,
+ dispose: one_byte_const_no_op,
+ lock: one_byte_const_no_op,
+ unlock: one_byte_const_no_op,
+ data: one_byte_const_data,
+ length: one_byte_const_length,
+};
 
 /// Compile-time function to determine if a string is ASCII. Note that UTF-8 chars
 /// longer than one byte have the high-bit set and thus, are not ASCII.
@@ -431,7 +419,7 @@ impl String {
  ) -> OneByteConst {
  is_ascii(buffer);
  OneByteConst {
- vtable: &ONE_BYTE_CONST_VTABLE.2,
+ vtable: &ONE_BYTE_CONST_VTABLE.delete1,
  cached_data: buffer.as_ptr() as *const char,
  length: buffer.len() as i32,
  }