A fast, growable array with stable pointers in C
August 5, 2025・6 minute read My last article about generic data structures in C was written to set the stage for today’s topic: A data structure that can be used in place of dynamic arrays, has stable pointers, and works well with arena allocators. It’s been independently discovered by different programmers over the years and so goes by different names. A 2001 paper called it a “levelwise-allocated pile” (bleh). Others call it an “exponential array”. In Zig’s standard library it’s “SegmentedLis