H. S. Teoh:
Just because you specify a certain compiler switch, it can cause
unrelated breakage in some obscure library somewhere, that
assumes modular arithmetic with C/C++ semantics.
The idea was about two switches, one for signed integrals, and
the other for both signed and unsigned. But from other posts I
guess Walter doesn't think this is a viable possibility.
So the solutions I see now are stop using D for some kind of more
important programs, or using some kind of safeInt, and then work
with the compiler writers to allow user-defined structs to be
usable as naturally as possible as ints (and possibly
efficiently).
Regarding safeInt I think today there is no way to write it
efficiently in D, because the overflow flags are not accessible
from D, and if you use inlined asm, you lose inlining in DMD.
This is just one of the problems. The other problems are syntax
incompatibilities of user-defined structs compared to built-in
ints. Other problems are the probable lack of high-level
optimizations done on such user defined type.
We are very far from a good solution to such problems.
Bye,
bearophile
