fix build errors

src/hncore/Digraph.zig

@@ -4,17 +4,17 @@ const std = @import("std");
 pub fn Digraph(comptime T: type, comptime lessThanFn: LessThanFunc(T)) type {
     return struct {
         ///
-        const Node = T;
+        pub const Node = T;
 
         /// A connection between 2 nodes.
         /// e.g.) `Conn { .from = X, .to = Y }` =>  "X is connected to Y"
-        const Conn = struct { from: T, to: T, };
+        pub const Conn = struct { from: T, to: T, };
 
         ///
-        const ConnList = std.ArrayList(Conn);
+        pub const ConnList = std.ArrayList(Conn);
 
         ///
-        const Error = error {
+        pub const Error = error {
             AlreadyConnected,
             NotConnected,
         };

src/hncore/Store.zig

@@ -3,16 +3,22 @@ const std = @import("std");
 /// A container for all existing instances of T.
 /// This is like a dedicated allocator for the type, T, with a refcount system.
 pub fn Store(comptime T: type) type {
-    const VTable = struct {
-        udata: ?*anyopaque = null,
-        deinitItem: ?*fn (?*anyopaque, *T) void = null,
-    };
     return struct {
         ///
-        const Item = T;
+        pub const Item = T;
+
+        ///
+        pub const VTable = struct {
+            ///
+            udata: ?*anyopaque = null,
+
+            ///
+            deinitItem: ?*fn (?*anyopaque, *T) void = null,
+        };
+
 
         /// A struct which holds an item and its reference count.
-        const Slot = struct {
+        pub const Slot = struct {
             item  : Item,
             refcnt: usize,
 
@@ -25,7 +31,7 @@ pub fn Store(comptime T: type) type {
         };
 
         ///
-        const Error = error {
+        pub const Error = error {
             DetectedItemLeak,
         };
 
@@ -36,14 +42,14 @@ pub fn Store(comptime T: type) type {
         vtable: VTable,
 
         ///
-        slots : std.ArrayList(Slot),
+        slots : std.ArrayList(*Slot),
 
         ///
         pub fn init(alloc: std.mem.Allocator, vtable: VTable) @This() {
             return .{
                 .alloc  = alloc,
                 .vtable = vtable,
-                .slots  = std.ArrayList(Slot).init(alloc),
+                .slots  = std.ArrayList(*Slot).init(alloc),
             };
         }
         ///