C++ pattern matching is coming

[Walter Bright]

On 10/23/2022 3:43 AM, IGotD- wrote:
> Can they reuse switch? In Swift they have pattern matching but they use the 
> switch keyword for their jack-of-all-trades switch statement. Problem with C++ 
> (and D) is that the switch statement is fallthrough by default. In order to fix 
> this historical mistake they need a complete new keyword.
> 
> This is something to fix in D3, remove fallthrogh by default.

Fallthrough by default was removed from D many years ago.

The awkward problem with re-using switch is that each case does not introduce a 
new scope. This raises all kinds of problems when using pattern matching to 
declare new variables.

A second awkward problem is that case statements can be placed inside nested scopes.

It's better to just leave switch as it is, and develop a new construct for 
pattern matching that hews to modern sensibilities.