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

[Kagamin via Digitalmars-d-learn]

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;
}
```