zig/doc/langref/test_incorrect_pointer_alignment.zig

const std = @import("std");

test "pointer alignment safety" {
    var array align(4) = [_]u32{ 0x11111111, 0x11111111 };
    const bytes = std.mem.sliceAsBytes(array[0..]);
    try std.testing.expectEqual(0x11111111, foo(bytes));
}
fn foo(bytes: []u8) u32 {
    const slice4 = bytes[1..5];
    const int_slice = std.mem.bytesAsSlice(u32, @as([]align(4) u8, @alignCast(slice4)));
    return int_slice[0];
}

// test_safety=incorrect alignment