Zig's Writergate: How the I/O Overhaul Killed Generic Poisoning

Writergate: Zig I/O Interface Overhaul

Zig's I/O interface overhaul, nicknamed Writergate, reached completion in August 2025 with the removal of generic writer and reader types. The new API uses concrete types with vtables, explicit buffering, and a required flush, addressing the problem of generic types 'poisoning' structs. This change enables async I/O, better performance, and precise error handling, with code depending on an Io instance similar to an Allocator.