[fidgewidge]

Yes, but my point is that there are only a few use cases for this, mostly in cryptography, and to ensure something is genuinely constant time you have to write in assembly. The routines needed are small enough and compilers hard enough to trust that you just bypass them in practice, so it's an odd choice for something to build into a language syntax.

[namkt]

My assumption is that it's not just the syntax, but that their compiler does the right thing. Though someone said it's based on LLVM, so who knows how much control they get.