A bug in 0.17's dereferencing comptime slices?

Help
,
1 
const print = @import("std").debug.print;

var x: [2]bool = .{false, true}; // global runtime value

pub fn main() void {
    // 's' is a comptime slice.
    const s: []bool = &x;
    print("{}\n", .{ @TypeOf(s) });    // []bool
    print("{}\n", .{ s[0] });          // false
    print("{}\n", .{ @TypeOf(s[0]) }); // bool
    print("{}\n", .{ @TypeOf(s.*) });  // bool (should be '[2]bool'?)
}
2

And the following code doesn’t compile.

var x: [2]bool = .{false, true}; // global runtime value

pub fn main() void { // error: genSetReg called with a value larger than dst_reg
    const s: []bool = &x;
    const arr = s.*;
    _ = arr;
}
3

Looks like the bug is more so in @TypeOf, seeing a dereference and returning the pointer child type without checking if the dereference is valid, silly considering only 2/4 pointer types support it.

Not sure why you expect the type of deref []T to be []T

4

Sorry, I meant [2]bool (instead of []bool).

5

Looks the problem only occurs for comptime slices derived from runtime global arrays.

const print = @import("std").debug.print;

var x: [3]u16 = .{ 1, 2, 3 };
const sx: []u16 = &x;

const y: [3]u16 = .{1, 2, 3};
const sy: []const u16 = &y;

pub fn main() void {
    print("{}\n", .{ @TypeOf(sx) }); // []u16
    print("{}\n", .{ @TypeOf(sy) }); // []const u16
    
    const ay = sy.*;
    print("{}\n", .{ ay[0] }); // 1
    
    const ax = sx.*;
    print("{}\n", .{ ax[0] }); // error: type 'u16' does not support indexing
}