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Questions - stdoptional

Using std::nullopt as a default value for an std::optional argument in C++17

This is a standard / good coding practice question. I've recently started using std::optional in my codebase. I think it's great (and verbose) for specifying an argument that's optional, so long as a ...
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heothesennoc

c++

c++17

default-arguments

stdoptional

Votes: 0

Answers: 1

Latest Answer

Yes, that is perfectly fine. It may be slightly verbose, but the interface is very clear. The only problem is that if someone wants to specify the last optional parameter, they will also have to spec...
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Ayxan Haqverdili

Is there any safe way to derive the offset of a T inside a std::optional<T>?

Given a std::optional<T> is it possible to derive the address of the std::optional<T> from the address of the T? possible implementation: template<typename T> struct myoptional { ...
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Frank Puck

c++

stl

stdoptional

addressof

Votes: 0

Answers: 1

Latest Answer

It is not specified where exactly in its storage std::optional stores the object. If you assume that the location of the object is always the same for the same type T, you can maybe (see below) use th...
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user17732522

What are monadic bind and monadic return for C++23 optional?

C++23 std::optional is finally getting some very useful additions. Since my knowledge of FP is very primitive I am wondering what is the syntax for the following two operations(that according to my go...
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NoSenseEtAl

c++

monads

stdoptional

c++23

Votes: 0

Answers: 3

Latest Answer

mbind (it doesn't exist, I'm mimicking Haskell's >>=) In C++-like pseudo-code, the monadic binding, let's call it mbind, should have such a signature: C<U> mbind(C<T>, std::function&...
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Enlico

Assigning values to std::array of std::optional objects

I am trying to fill a std::array of std::optional objects as below. class MyClass { private: int distance; MyClass(int x, int y); friend class MasterClass; }; MyClass::MyClass(int x, i...
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TeenyTinySparkles

c++

c++17

stdarray

stdoptional

Votes: 0

Answers: 1

Latest Answer

Looks like maybe you are coming from Java, or C#. When you assign a value in c++, it is rare that you will use new. The issue is, that you are basically doing this: std::optional<MyClass> o = ne...
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Fantastic Mr Fox

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