Implicit error types crash stage1

[shawnl]

If you use an implicit error in a switch

catch |err| switch (err) {
.MyError =>
}

it will crash with

zig: ../src/ir.cpp:21037: IrInstruction* ir_analyze_instruction_check_switch_prongs(IrAnalyze*, IrInstructionCheckSwitchProngs*): Assertion `start_value->value.type->id == ZigTypeIdErrorSet' failed.

Glad I finially figured out what the bug was...so I can work around it and continue hacking.

[LemonBoy]

The parser recognizes .MyError as a ZigTypeIdEnumLiteral, we can either reject this with a proper error instead of an assertion or make it work by teaching the compiler how to cast it to a ZigTypeIdErrorSet.

[shawnl]

or make it work by teaching the compiler how to cast it to a ZigTypeIdErrorSet.

+1

[andrewrk]

It's a compile error, because:

const Error = error {Bad};
const Enum = enum {Bad};
fn foo() Error!Enum {
    return .Bad; // what does this do?
}

Feel free to open a proposal to discuss more.