isDefaultGpuCpuAccelerators function
Whether accelerators is exactly the default "try GPU, fall back to CPU"
set of {Accelerator.gpu, Accelerator.cpu}.
Callers use this to distinguish the permissive default from an explicit accelerator request that must be honoured as-is.
Implementation
bool isDefaultGpuCpuAccelerators(Set<Accelerator> accelerators) {
return accelerators.length == 2 &&
accelerators.contains(Accelerator.gpu) &&
accelerators.contains(Accelerator.cpu);
}