> are there important projects that do this intentionally?
Expecting integer overflow to be two's complement is so common that successors like Java, Go, and Rust all standardized on it, used by hashing algorithms and more: https://github.com/rust-lang/rfcs/pull/560
> In any case, compiler authors are going to follow the C standards, not you hypothetical "C-in-practice" standards
"The optimizer does go to some effort to "do the right thing" when it is obvious what the programmer meant (such as code that does "* (int *)P" when P is a pointer to float)." --blogpost by the second most widely used C compiler, clang/llvm: http://blog.llvm.org/2011/05/what-every-c-programmer-should-...
Expecting integer overflow to be two's complement is so common that successors like Java, Go, and Rust all standardized on it, used by hashing algorithms and more: https://github.com/rust-lang/rfcs/pull/560
> In any case, compiler authors are going to follow the C standards, not you hypothetical "C-in-practice" standards
"The optimizer does go to some effort to "do the right thing" when it is obvious what the programmer meant (such as code that does "* (int *)P" when P is a pointer to float)." --blogpost by the second most widely used C compiler, clang/llvm: http://blog.llvm.org/2011/05/what-every-c-programmer-should-...