private.zig

const std = @import("std");

const PrivateImpl = struct {
    secret: i32,
};

pub const MyStruct = struct {
    public_field: u32,
    private_data: *anyopaque,
    allocator: std.mem.Allocator,
    
    pub fn init(allocator: std.mem.Allocator, public_val: u32, secret: i32) !MyStruct {
        const private = try allocator.create(PrivateImpl);
        private.* = PrivateImpl{ .secret = secret };
        
        return MyStruct{
            .public_field = public_val,
            .private_data = private,
            .allocator = allocator,
        };
    }
    
    pub fn deinit(self: *MyStruct) void {
        const private: *PrivateImpl = @ptrCast(@alignCast(self.private_data));
        self.allocator.destroy(private);
    }
    
    pub fn getSecret(self: *const MyStruct) i32 {
        const private: *const PrivateImpl = @ptrCast(@alignCast(self.private_data));
        return private.secret;
    }
};