Re: [boost] Adding optional<T&> find like method to associative containers in boost.

On Mon, Dec 16, 2024 at 12:02 PM Andrzej Krzemienski wrote:

pon., 16 gru 2024 o 11:36 Ivan Matek via Boost napisał(a):

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Hi everybody,

I presume somebody thought of this before but for some reason it never happened, but just in case it was never discussed I wonder if people here believe adding an nicer version of find(with different name obviously) to associative containers in boost would be beneficial?

Since boost::optional allows references this would work.

It does, but conceptually optional as a return type is not much different than T* return type.

Well I do not think so, as optional avoids using raw pointers(I understand some do not care about this fact, but I think many people do), and as mentioned before people like to chain https://devblogs.microsoft.com/cppblog/cpp23s-optional-and-expected/ operations on optional. I could type here few more sentences, but I think Barry did it better than I ever could. https://brevzin.github.io/c++/2021/12/13/optional-ref-ptr/

*All the operations in the orange circle are highly irrelevant to this problem and would be completely wrong to use. They are bugs waiting to happen.*

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boost::optional did not get all the updates C++23 std::optional got, e.g. transform that make this usage compose nicely, but those could be added to boost::optional.

Note that boost::optional has had the "monadic interface" for a while. It just uses a different name (map) as at the time we were adding it, a monadic interface in std::optional was not a thing.

my bad, sorry, I just googled and ended up here, did not find it: https://www.boost.org/doc/libs/1_87_0/libs/optional/doc/html/optional/refere...