Empty classes dislike being placed into vectors

[brson]

class c {
    new() { }
}

fn main() {
    let a = c();
    let x = [a];
    let y = x[0];
}

rust: upcall fail 'bounds check', /home/banderson/Dev/rust/src/test/run-pass/test.rs:8
rust: domain main @0x66e8e30 root task failed

Also:

class c {
    new() { }
}

fn main() {
    for [c()].each {|i|
    }
}

==19949==
==19949== Process terminating with default action of signal 8 (SIGFPE)
==19949==  Integer divide by zero at address 0x40339A836
==19949==    at 0x401068: vec::unpack_slice7::_79a2ea93cf50478f::_00 (in /home/banderson/Dev/rust/build/x86_64-unknown-linux-gnu/test/run-pass/test.stage1-x86_64-unknown-linux-gnu)
==19949==    by 0x400F0E: vec::each6::_67468c156592b8bf::_00 (in /home/banderson/Dev/rust/build/x86_64-unknown-linux-gnu/test/run-pass/test.stage1-x86_64-unknown-linux-gnu)
==19949==    by 0x400E90: vec::extensions::each5::_4ad0f86fc13c8027::_00 (in /home/banderson/Dev/rust/build/x86_64-unknown-linux-gnu/test/run-pass/test.stage1-x86_64-unknown-linux-gnu)
==19949==    by 0x400C06: main::_f8ae15773a042ac1::_00 (in /home/banderson/Dev/rust/build/x86_64-unknown-linux-gnu/test/run-pass/test.stage1-x86_64-unknown-linux-gnu)
==19949==    by 0x400D1B: _rust_main (in /home/banderson/Dev/rust/build/x86_64-unknown-linux-gnu/test/run-pass/test.stage1-x86_64-unknown-linux-gnu)
==19949==    by 0x5341D1A: task_start_wrapper(spawn_args*) (rust_task.cpp:153)

[brson]

This seems to be a problem with empty classes specifically.

[catamorphism]

Yeah, classes without dtors are basically treated like records in trans, so I can see why a record with no fields would cause problems. I'll look at this.

[catamorphism]

brson and I agreed we should just forbid classes with no fields, since there are no empty record types either. I will implement that.

[kud1ing]

Does that mean classes are only meant for state-management and if you want to have polymorphic functions, you should go for interfaces/implementions?

[brson]

@Lenny222 to be clear, I still think empty classes should be allowed eventually. We should just cover the limitation with a compiler error for now instead of a crash.