dmd foreach loops throw exceptions on invalid UTF sequences, use replacementDchar instead

[Ola Fosheim Grøstad]

On Thursday, 11 November 2021 at 01:31:46 UTC, Elronnd wrote:
> I agree this should be required.  If you want something which 
> is not valid UTF-8, _do not put it into a string_.  Use ubyte[].

Exactly.

> Go further: require a runtime check on cast from ubyte[] to 
> char[] (expensive), and on slicing char[] (cheap).  (If you 
> abuse unions you are on your own; but obviously that is not 
> allowed in @safe code, so has the same limitations as e.g. 
> boundschecking.)

The compiler could do such checks in an extra-solid-debug-mode. 
That could certainly improve unit-testing and other testing. In 
such a mode you could also do overflow checks for signed integers 
(if they are changed so they don't wrap).