Add non-const getters to iterator

[kiwixz]

Iterator has const operators since #685 (see here).

This makes it impossible to do in-place update (modify the value and pass it to update) when iterating the database. I think we should add non-const overloads.

Thanks!

[fnc12]

hi. Can you provide a small code snippet to repro it please?

[kiwixz]

Sure ! Here you go:

struct S {
    int id;
    int value;
    int some_other_information;
};

void f() {
    auto db = make_storage(path,
                        make_table("currency",
                                    make_column("id", &S::id, primary_key()),
                                    make_column("value", &S::code),
                                    make_column("some_other_information", &S::some_other_information)));

    for (auto& s : db.iterate<S>()) {
        // get a new value here for the id, so we want to update it in database
        int new_value = 42;

        // easy way (not working, s is actually a const&)
        s.value = new_value;
        db.update(s);

        // longer way (working)
        db.update(S{s.id, new_value, s.some_other_information});
    }
}

[fnc12]

@kiwixz BTW you can use const_cast which will make the work. Why don't you use this approach?

[kiwixz]

I would not want to do that, if I'm allowed to modify the value then it should not be returned to me as a const&. const_cast says "I dont care if I'm not supposed to, I will modify this anyway".

[fnc12]

PR https://github.com/fnc12/sqlite_orm/pull/1229

[fnc12]

merged. Please check dev branch. Also it will be merged into master on the next release

[kiwixz]

Works great, thanks!