Questions tagged [variant-type]
A data type or a class designed to emulate a data type that holds a single value of a type that is either from an explicitly (compile-time) specified list, or arbitrary. The actual type of the stored value is only known at runtime.
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C++ compile time polymorphism example [closed]
I found an example using std::variant to provide compile time polymorphism as a possible optimisation to runtime polymorphism in 'Software Architecture Using C++', https://github.com/PacktPublishing/...
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A parse function for text line with fields separated by a comma with the known number and their type, simplified version
simplifying this question, taking most of the comment into considerations, I ended up with this version, looking for some feedback
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Transpose types variadicly
I want to do template metaprogramming to compute the conversion from std::variant<Ts...> to ...
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C++ Minimal CSV parser cut2
Looking at this questoin, I was inspired by the idea and the approach, so I tried to write a second version of the code, taking most of the comments into considerations.
Please note that I am still ...
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C++: Visit Any Type Holding Other Types (`std::any`, `std::variant`, etc.)
Intro
I want to visit the value held by a class, which could be of multiple types. This class is very similar to a std::any, so I will be using this in this ...
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Dynamic type implementation in C
Dynamic Type - [ int, char, bool, ... => dtype ]
Dynamic Type in C, A project that I had been thinking of for a while and made it.
How it works ?
Dtype currently is same as ...
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Helper functions for use with std::variant without an actual object
Sometimes, you want to an type of a particular index in an std::variant, and do something with that type without having an actual object. An example use-case would be de-serialization. What do you ...
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Haskell: implementing Read for a custom dynamic value type
I'm using Haskell to interpret a dynamically-typed language. I have a sum type called Value which can represent some basic objects:
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visit for std::any
While solving an online excersise I have written some basic implementation for a visit function that works with std::any.
The ...
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Token class implementation with std::variant
So I've been trying to implement a Token class in C++. At first I wanted to use a simple enum class to store the Kind of the ...
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Type agnostic, statically allocated, thread-safe queue in C
I need a queue in C for an embedded application in which I cannot allocate memory dynamically.
I avoided using void* for the queue elements (which is not convenient ...
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C++ My implementation of a simple sum type (variant)
Here is a simple variant type I have made. For simplicity, it only can handle two different values. I am planning on using this to create a variadic variant template, using inheritance and recursion.
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Simplify & Reduce steps in the IsDistinct function
Because I often have to deal with two Variants that may or may not be Null, we need a null-safe equality test, so I came up with ...
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Assign a variant to a variant
Quick review:
I've been writing API code which receives user input that can come as either an object or a value type - a problem outlined here.
In order to write an unknown data type to a variable, ...
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YAAI (Yet another any implementation)
I am a C# game developer currently learning C++ and this is my second big-ish project (the first one being a vector implementation).
This time I opted for implementing a mot-a-mot ...
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C++17 Either implementation for error handling [closed]
This is a C++17 Either implementation for error handling.
First intent is I want to improve myself.
Second intent is I want to create a more expressive solution than variant for exception free error ...
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Implementation of std::any
Today, I decided to implement std::any using the cppreference page. I've never actually used std::any before and after seeing ...
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Type erasure in Rust
This is a very stripped-down version of a crypto library I am writing. There are cryptographic algorithms like RSA, DSA, ECDSA, EdDSA, ... which all have a similar pattern of having a private key, a ...
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Swift append an array when it's been declared as Any
I'm learning Swift and I have a following problem: I create a dictionary containing some data, one of which is stored as an array. I want make an operation on this array to add some info. Currently I ...
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Creating an array of distinct objects with an identical method that can be evaluated (mapped) at compile-time (constexpr)
In a ray tracing project that I'm trying to make compile-time (constexpr) for fun and challenge, I've run into a bit of an issue: I have an object (intersection) that needs to refer to one of a group ...
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create sorted vector of content of two binary search trees in sorted order
You are given two binary search trees, the goal is produce a sorted array of elements containing elements from both the trees.
I wanted to know if there is a simpler approach, and if the use of ...
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Template Metaprogramming Discriminated Union
std::variant and boost::variant do not require the types involved to be unique, but lose some functionality when types repeat.
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Variant implementation in C++
I've been fiddling with templates and compile time stuff i implemented a variant container and wanted some opinions and recommendations this is just a learning exercise, a couple template classes not ...
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Value semantic type eraser
I've been using std::unique_ptr for cases where I want to store a derived-type value with type erasure, and felt that unique_ptr being nullable was an undesirable ...
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Simple C++ alternative to exceptions for embedded systems
I have researched ways to implement a simpler alternative for C++ exceptions. The problem I had with exceptions was the complex and not-portable stack unwinding process which makes it hard to ...
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Custom basic std::variant
I was amazed by std::variant and got inspired to write my own. For now, it supports constructor+destructor pair, assignment operator and ...
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C++ variant and variant subsets
I seem to be in a love-hate relationship with C++. It can make some parts of your code elegant and easy to grasp, and some others become an inconceivable mess. And it's not the language itself causing ...
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An implementation of a static any type
This describes type util::any<std::size_t size, std::size_t align> - an implementation of std::any with a static size/no ...
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Variant class using generic programming
My goal is to learn a bit more about generic programming in C++. So, one of the trickiest things I've heard you can do is creating a Variant class. This took me a while and I needed to read and study ...
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Any class implementation - follow-up
Based on the previous question, I have improved it to make it insert regular function. Also, I have implemented a new template approach to obtain the signature from any function by testing its ...
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Runtime compiler for getting/setting runtime property values
I've been playing about with runtime compilation to allow me to get/set runtime property values in C#, and so far I have come up with a class.
This allows me to write code like the following which ...
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Any class implementation
I was inspired from question here, to implement function container that holder any kind of function by using boost::any, I have carried on and extend it further to make the functions holder accept ...
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Trivial full-fledged variant for constexpr (proof of concept)
I want to show you how to implement variant like boost::variant, but almost for constexpr, ...
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Type-agnostic BubbleSort in C
I'm trying out different sorting algorithms for learning purposes, here I'm doing a "type-agnostic" bubbleaort.
I modeled the function signature after the standard library's ...
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Storing collections of objects of any type
I've put together a class whose goal is to store objects of arbitrary type, with each type having its own vector for contiguity. I'd like to gather advice on what I have so far before I carry on.
Let ...
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union based approach to implement variant
This implementation of discriminated union based on C++ inherent unions and inspired by this and this articles.
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Multiple dispatch with variant and multi visitation in C++
The following program is a demonstration of variant and double visitation used to obtain double dispatch between the elements of two inhomogeneous containers. Most of the work is done at compile time. ...
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Variant class with full move support
I tried to write my own variant class, that is fully move-semantics enabled. WRT to implemented visitors, they don't require any policy and like to be derived from <...
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Yet another 'any' class implementation, named 'some'
This is a follow-up of 'any' class implementation. After posting my answer, I kept working on the code towards parameterizing with respect to memory management as I had promised. I ended up in some ...
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Clone of Boost Variant
As part of learning C++, with special emphasis on C++11, I wanted to implement the equivalent of Boost's Variant (located here). My code is available at variant.hpp, with the current version given ...
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C++11 Any class
This is a polymorphic wrapper capable of holding any type. (It is loosely based on boost::any)
In particular, this is useful when you want to store a ...
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boost::any replacement with std::unique_ptr support
I needed a boost.any look-a-like, that could handle a std::unique_ptr. I came up with this. Please provide some C++11 criticism.
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