Questions tagged [optional]
Use this tag for code that implements (or depends heavily on) a data type that can be empty or hold a value.
50
questions
3
votes
1
answer
139
views
Partial specialization of class template with minimal code duplication
I have a class template that stores an std::optional<T>. A very reduced version of the class template looks like this:
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8
votes
3
answers
3k
views
C++ std::optional implementation
Took a shot at implementing a subset of std::optional functionality. A lot of core features are there but some things like converting constructors, etc are missing ...
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-3
votes
1
answer
225
views
std::optional<std::size_t> correct values comparison [closed]
I need to compare two std::optional<std::size_t> variables, considering all possible cases(both std::nullopt or one of ...
- 95
0
votes
2
answers
97
views
Java spring controller method to trigger e-mail verification procedure [closed]
For readability sake, is it better to use optionals or write my code in an iterative manner?
Here's a route I'm working on, does this look readable do you?
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5
votes
1
answer
531
views
Filtering an Option Result using a boolean Result in Rust
I'm trying to rewrite one of my pet projects in Rust, and when I was faced with the problem of filtering a Result<Option<T>, E> via a ...
3
votes
1
answer
542
views
Rust idiomatic option handling
Is there a neater way of handling the option response from req.cookie() in this code block (line 3 onwards)? Id like to avoid the nested if statements, and multiple ...
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3
votes
3
answers
2k
views
Concatenating optional strings in Scala
I have two optional strings, any of them can be None. I want to create their combination with a delimiter between them if they both exist.
I expect to be able to come with a more concise and nicer ...
- 238
2
votes
2
answers
101
views
Treating Optional values
I have a situation when there could be and could not be values in database, which is why i return optional, so the response object that goes back to the UI could be different depending on the ...
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-1
votes
1
answer
3k
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Using Java Optional.ofNullable() instead of if/else or ternary conditional [closed]
I've recently reviewed code twice, from two different authors, where the author has cleverly used Thingy z = Optional.ofNullable(x).orElse(y) rather than using, say,...
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3
votes
2
answers
84
views
A Start button handler
I was told my code contains a lot of force unwrapping. I thought it's okay to do that if I am sure that the value operated won't be nil:
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- 143
3
votes
1
answer
646
views
Updates or creates an entity based on if a value is present in an Optional
I need to get car info from a 3rd party web service and persist the data in my application DB. If my DB already has the car, I only update property values that may have changed. Otherwise, I create ...
- 299
2
votes
0
answers
57
views
Maybe with a structural pattern matching interface
With a reference implementation for PEP 622 now available in a Jupyter playground, I decided to copy over my favourite feature of Rust in full to Python.
Note: this won't be released until Python 3.10 ...
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3
votes
1
answer
325
views
Unwrapping optionals for max of a 2D array in swift
I'm working in swift and I've got a custom class Array2D to handle fixed-width, two-dimensional arrays of integers. What I'm trying to do is write a simple, ideally-...
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4
votes
1
answer
2k
views
C++ Optional Reference
Here is a good article on an optional reference type in C++. They discuss std::optional<T&>, but as that doesn't compile I have made my own.
One purpose ...
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2
votes
1
answer
9k
views
Best practice to initialize instance variables for a POJO when values are null
I am using Java 8. I haven't found another question that fits mine exactly, and I've come across some conflicting information on best practices with what I'm trying to do.
I'm creating a POJO which ...
- 33