Union Types and Option Types

Copper, the "better C" language created by an unnamed developer, is shifting its type-system experimentation from general union types to a trimmed-down option type (T|Nothing) after union types proved too complex for a minimalistic low-level language. The earlier union implementation used a tag for the general T1|T2|...|Tn case but handled Pointer|Nothing without a tag, discriminating via the NULL pointer for speed and external-library integration. Restrictions included no nested unions, order-significant types (T1|T2 differs from T2|T1), and no compatibility between unions such as T1|T2 and T1|T2|T3, which simplified tag assignment but limited flexibility. The developer found the feature genuinely useful, mainly for T|Nothing and T|Error patterns, but concluded the compiler complexity outweighed the benefits; error handling will revert to returning an error plus a value. The new option type reserves a value to represent nil, with implementation details still emerging. What to watch: whether the narrower option type delivers the safety benefits without the compiler burden that sank full union types in Copper.