disallowed-types = [
    "std::collections::HashMap",
    "std::sync::atomic::AtomicU32",
    "syn::TypePath",
    "proc_macro2::Ident",
    "std::thread::Thread",
    "std::time::Instant",
    "std::io::Read",
    "std::primitive::usize",
    "bool",
    # can give path and reason with an inline table
    { path = "std::net::Ipv4Addr", reason = "no IPv4 allowed" },
    # can use an inline table but omit reason
    { path = "std::net::TcpListener" },
]