I like TOML too, but speaking of footguns, there is one where it comes to serialization. If you have something like:

    struct Foo {
        int bar;
        Baz baz;
        int quux;
    }

... you can't naively serialize this like:

    [foo]
    bar = 5

    [foo.baz]
    ...

    quux = 6

because that makes `quux` a property of `foo.baz`, not of `foo`.

The serializer has to be smart enough to recognize that primitive fields have to be serialized before object fields. As a practical example, Rust's TOML library is not smart enough to do so, though it does at least detect when this would happen and fails with a runtime error. (The workaround is to change your type definition to reorder the fields yourself.)

Ref: https://play.rust-lang.org/?version=stable&mode=debug&editio...