Possible 'pure' bug with int[] slice. Programming in D page 174

[Steven Schveighoffer]

On Wednesday, 8 October 2025 at 08:48:12 UTC, Kagamin wrote:
> To be pedantic, strong purity requires immutable arguments, 
> const are not enough:
> ```
> void main()
> {
> 	import std.stdio : writeln;
>
> 	int[] numbers = [5, 6, 7, 8, 9];
> 	writeln("numbers before: ", id(numbers));
> 	numbers[0]=1;
> 	writeln("numbers after : ", id(numbers));
> }
>
> const(int)[] id(const int[] p) pure
> {
> 	return p;
> }
> ```

Yes, thank you for the correction.

I got this confused with pure factory functions, where returning 
a mutable item from const parameters allows the compiler to 
assume the return value is unique.

-Steve