Unions

Discriminated Unions

Learn how F#'s discriminated unions model a closed set of named cases, each optionally carrying data, with compiler-enforced exhaustive pattern matching.

Interfaces and Unions

How GraphQL's two abstract types — interfaces with guaranteed shared fields, and unions with no shared contract — let a single field return polymorphic results.

Unions in C

Learn C unions: syntax, how members share the same memory, sizeof(union) rules, and the type-punning pitfall of reading a member you did not last write.

Discriminated Unions in TypeScript

Use a shared literal 'tag' property across union members so TypeScript can narrow exactly which member you're handling in a switch or if.

C Structs & Unions Cheat Sheet

Explains defining and using C structs and unions, including member access, typedef, padding, bit-fields, and memory layout differences.