In C++23, monadic operations in std::optional was adopted, and later on std::expected. Why were monadic operations like and_then, transform, and or_else not included in the main paper?
Why are there no monadic operations in std::expected?
1.2k Views Asked by Desmond Gold At
1
There are 1 best solutions below
Related Questions in C++
- C++ using std::vector across boundaries
- Linked list without struct
- Connecting Signal QML to C++ (Qt5)
- how to get the reference of struct soap inherited in C++ Proxy/Service class
- Why we can't assign value to pointer
- Conversion of objects in c++
- shared_ptr: "is not a type" error
- C++ template using pointer and non pointer arguments in a QVector
- C++ SFML 2.2 vectors
- Lifetime of temporary objects
- I want to be able to use 4 different variables in a select statement in c ++
- segmentation fault: 11, extracting data in vector
- How to catch delay-import dll errors (missing dll or symbol) in MinGW(-w64)?
- How can I print all the values in this linked list inside a hash table?
- Configured TTL for A record(s) backing CNAME records
Related Questions in C++23
- C++ NN implementation only trains to uniform output value
- lambda function with incomplete type
- How to do `import std` with CMake
- How can to change cursor for MessageBox()? WinAPI, C++ (23)
- C++ Observer design pattern, prevent object from being reallocated
- When to use CRTP over explicit object parameter in c++23?
- How to get individual chunks from std::chunk_by return value?
- c++23 building with <stacktrace> library
- Which version of the C Standard Library does the C++23 Standard incorporate?
- Why do std::ranges::set_difference, std::ranges::set_intersection do not work on std::unordered_set?
- How to check if a template typename is the same as another type but ignoring template parameters
- auto ( expression ) in direct initialization argument
- Visual C++ mdspan
- C++ Phase 1 Translation Set of Source File Characters: Before vs. Post C++11, before C++23
- Is this behavior of std::expected with move-only types a MSVC bug or undefined behavior?
Related Questions in STD-EXPECTED
- Is this a correct convenience wrapper for std::expected?
- Compressed std::expected
- Is this behavior of std::expected with move-only types a MSVC bug or undefined behavior?
- std::expected, references, and std::reference_wrapper
- What is std::expected in C++?
- C++ is there an implementation of std::expected that doesn't consider a default constructed `expected` to have a value?
- When to use std::expected instead of exceptions
- How to avoid calling the destructor twice when using a factory function with a std::expected return without runtime costs
- Why are there no monadic operations in std::expected?
- Why does std::expected<T, E> require T to be copy-constructible if it is copy-assignable?
- What to do about exceptions which don't fit your Expected error type?
- How to use std::expected in conjunction with std::transform?
- std::unexpected constructor constraint
- Is that possible to upcast erased type without RTTI?
Trending Questions
- UIImageView Frame Doesn't Reflect Constraints
- Is it possible to use adb commands to click on a view by finding its ID?
- How to create a new web character symbol recognizable by html/javascript?
- Why isn't my CSS3 animation smooth in Google Chrome (but very smooth on other browsers)?
- Heap Gives Page Fault
- Connect ffmpeg to Visual Studio 2008
- Both Object- and ValueAnimator jumps when Duration is set above API LvL 24
- How to avoid default initialization of objects in std::vector?
- second argument of the command line arguments in a format other than char** argv or char* argv[]
- How to improve efficiency of algorithm which generates next lexicographic permutation?
- Navigating to the another actvity app getting crash in android
- How to read the particular message format in android and store in sqlite database?
- Resetting inventory status after order is cancelled
- Efficiently compute powers of X in SSE/AVX
- Insert into an external database using ajax and php : POST 500 (Internal Server Error)
Popular Questions
- How do I undo the most recent local commits in Git?
- How can I remove a specific item from an array in JavaScript?
- How do I delete a Git branch locally and remotely?
- Find all files containing a specific text (string) on Linux?
- How do I revert a Git repository to a previous commit?
- How do I create an HTML button that acts like a link?
- How do I check out a remote Git branch?
- How do I force "git pull" to overwrite local files?
- How do I list all files of a directory?
- How to check whether a string contains a substring in JavaScript?
- How do I redirect to another webpage?
- How can I iterate over rows in a Pandas DataFrame?
- How do I convert a String to an int in Java?
- Does Python have a string 'contains' substring method?
- How do I check if a string contains a specific word?
Update:
std::expectedin C++23 will have monadic operations.The
std::expectedproposal is very old. The adopted revision is P0323R12, which already suggests a long life, but that paper even predates the P-numbering system and started out as N4015, dated May 2014.I bring this up because
std::expected, even by itself, has taken a very long time to wind its way through the process. In contrast, the monadic operations forstd::optionalpaper only first appeared in October 2017. And since then it was just a long slog just to getstd::expectedat all.There is a paper proposing monadic operations for
std::expected, that's P2505R0, but at this point it's very incomplete and needs a lot of work. The design window for new C++23 features is closed, but I wouldn't be surprised if there were an NB comment requesting it in later anyway.At least we finally have
std::expected.Coming in here a few months later, there was an NB comment requesting the monadic operators for
std::expectedand P2505R5 was adopted for C++23 in Kona in November 2022.