Fun surprising things

[Kagamin]

On Wednesday, 31 October 2018 at 14:54:48 UTC, Patrick Schluter 
wrote:
> 01 is the other possible result. It all depends in what order a 
> and b are called. ~ is not a sequence point (does D even have 
> that typical C notion of sequence points?) so the order of 
> evaluation is at the discretion of the compiler.

In C function call is a sequence point, undefined order applies 
only to expressions without sequence points. BTW to!string 
allocates memory from GC which involves a mutex lock, which can't 
possibly have undefined order.