ikskuh / any-pointer

A type erasure library for Zig that is meant to be eventually upstreamed to std

any-pointer type erasure

This package provides a single file any-pointer.zig that implements a type-erased pointer for Zig.

This pointer type supports three functions make, cast and isNull and exports the symbol null_pointer.

const AnyPointer = @import("any-pointer").AnyPointer;

var i: u32 = 0;

const erased = AnyPointer.make(*u32, &i);

const ptr = erased.cast(*u32);

ptr.* = 42;

std.debug.assert(!ptr.isNull());
std.debug.assert(i == 42);

In safe modes (Debug and ReleaseSafe) cast will type-check the pointer and might @panic when a type confusion would happen.

Usage

Just add a package pointing to any-pointer.zig to your project.

The package will export three types:

• SafePointer, which will provide type checking and panics in safe modes.
• UnsafePointer, which will not provide type checking and will only have the size of a single pointer.
• AnyPointer, which will be SafePointer in safe modes and UnsafePointer in unsafe modes.

In addition to make, cast and isNull, SafePointer also has the function tryCast which works like cast, but will return an optional.