If you do not use dart:ffi you may stop reading now.
We're making a breaking change where invocations of dart:ffi's sizeOf<T extends NativeType>(), Pointer<T>.elementAt(), Pointer<T extends Struct>.ref, and Pointer<T extendsStruct> require T to be compile-time constants
We're also making a breaking change where subclasses of Struct are required to have at least one field.
These changes are being made for the Dart 2.12 release.
Please add comments to the issues if you have concerns about these changes.