On Tuesday, 12 April 2022 at 22:23:18 UTC, ag0aep6g wrote:
On Tuesday, 12 April 2022 at 19:54:13 UTC, wjoe wrote:
Especially since it's only a promise and the compiler accepts
this:
void foo (const(char)[] arr)
{
cast(char[])arr[0..3] = "baz";
}
string bar = "123";
foo(bar);
assert(bar=="baz");
But I could cast away const and modify the string bar.
No, you could not. You're relying on undefined behavior there.
Just because the compiler accepts something, doesn't mean it's
ok.
If you want to be guarded against wandering into undefined
territory, that's what @safe does. With @safe, the cast doesn't
compile.
Undefined behavior yes, but regardless the example proves it can
be done in @system code.
A few versions ago, possibly due to a bug or regression, the
compiler didn't complain in @safe code either.
Of course you are correct academically. However, since it's
possible, I'd wager my last hat that code like this is out in the
wild.
