[ComputerGuru]

I was going to say that Microsoft appears to have chosen to address this at the library level with brilliantly optimized frozen and immutable variants of the collections, but you beat me to it.

It probably would have been easier and cleaner to implement some form of `restrict` and `const` semantics (or maybe move, like you mentioned) than to work as hard as they did to come up with a still sub-optimal solution, but the performance they’ve managed to eek out of the frozen and immutable variants is to be commended.

[colejohnson66]

Oh, for sure. Microsoft's dotnet team deserves massive props for the effort they've put into the runtime. As for why there's no `restrict`, `const`, or `move` semantics, it seems the runtime team is extremely averse to modifying the CIL's capabilities as it would be a breaking change; They'd rather have the library team add classes/attributes that the runtime recognizes and special cases.