Allocators: Best Practices & Anti-Patterns

[jumpnbrownweasel]

There were a couple recent threads discussing different aspects of this question.

Freeing memory on error

Here is a simple tree-like structure representing mathematical expressions. I made two helper functions to create expression easily with this syn pub const Binop = enum { ADD, SUB, DIV, MUL, POW }; pub const Expr = union(enum) { integer: i128, binop: struct { op: Binop, lhs: *Expr, rhs: *Expr, }, pub fn fromInteger(value: i128, allocator: std.mem.Allocator) std.mem.Allocator.Error!*Expr { const e = try allocator.create(Expr); e.* = Expr{…

Basic Question on Allocation

This is perhaps too vague a question, but it’s on how to approach memory and such in Zig. My background/understanding is we have the stack where we’d usually store transient state. However, some state must be dynamically allocated. This can be either when the alliocation amount is unknown or when the lifetime of a resource isn’t bound to function scope. Hence why there is malloc in C. Malloc is a general purpose purpose allocator handling requesting and tracking memory from the OS, so the idea …