inferred union cast

gistfile1.txt

pub const Leaf = struct {
    frequency: u32,
    value: u8,
};

pub const Branch = struct {
    frequency: u32,
    left: ?*Node,
    right: ?*Node,
};

pub const Node = union(enum) {
    Branch: Branch,
    Leaf: Leaf,
};

pub fn main() !void {
    const node: Node = Node {
        .Leaf = Leaf {
            .frequency = 1,
            .value = 1,
        }
    };
    const Tag: @TagType(Node) = node;
    const is_branch = node == Tag.Branch;
}

➜  git:(master) ✗ zig build-exe asdf.zig && ./asdf
asdf.zig:25:34: error: no member named 'Branch' in enum '@TagType(Node)'
                const is_branch = node == Tag.Branch;