Category "c++"

What is struct Cleaner <T*> mean?

What is struct Cleaner <T*> mean? Is it specific the second Cleaner can only accept the type of pointer? what is the terminology of this usage in C++? te

Is it possible to determine if a pointer points to a valid object, and if so how? [duplicate]

I was reading C++ Is it possible to determine whether a pointer points to a valid object? and the correct answer in this thread is that no, yo

How to create a "factory function" for a templated class?

How would someone go about implementing a factory function for a templated class? Either my google searches aren't looking for the right thing, or I am misunde

Parameter pack iteration

Why this code doesn't compile ? #include <iostream> #include <typeinfo> template <typename ...Ts> void f(); template <typename T> void

Incrementing iterator from end to begin

I want to iterate over a vector and when reaching the end it should loop back to the front. This is a small example which does not compile #include <vector&g

Vector point std::vector<cv::Point>

I am trying to draw a trajectory on an image and saving these trajectory points as std::vector<cv::Point> trajectoryPoint and I would like to access the

C++ change parent class based on option

There is a Student class inherited from Person. And there is Student class inherited from University. I want to change the parent class Person, University based

GCC -Wimplicit-fallthrough is not warning when I miss [[fallthrough]]

I am using GCC version 8.3 and have a switch statement: #include <iostream> enum class Type : char { Value1 = 'A', Value2, Value3, Value4

How do I start my project in Unreal Engine 5?

I've tried to create my new Unreal Engine 5 project from a tutorial with c++ and when I try it comes up with this: Running C:/Program Files/Epic Games/UE_5.0EA/

Remote Desktop - getting session information (id, session name, etc.) from client side

Let's consider the following scenario: take a Windows Server instance (2012 or newer), with multiple user accounts. Each of those accounts needs to run an indiv

Configuring compilers on Mac M1 (Big Sur, Monterey) for Rcpp and other tools

I'm trying to use packages that require Rcpp in R on my M1 Mac, which I was never able to get up and running after purchasing this computer. I updated it to Mon

How to manually disable libstdc++ in CMake for Clang

Recently I'm configuring a new project in language C and C++ using both CMake and llvm Clang with Visual Studio Code for a program where EVERY exact object or l

What to use on Nodejs addons. Node.h or Napi.h

I have some pretty simple questions. What is the main difference between node.h and napi.h. What should I use for normal/personal use case. Why are there more "

Inserting non-const pair into `std::unordered_map` is slower than const pair

I have some code like these (from cppcon), when inserting a non-const pair into a unordered_map, the performance is very different to inserting with a const one

QProcess does not work if the path in argument list has a whitespace

I want to execute following command using QProcess, that works in cmd already if executed: C:\\myApplication\\tools\\dcmodify.exe -v -ie -gin -nb -ma (0010,0010

c++20 coroutines: boost asio co_spawn blocks from another coroutine

I do not know if this is the expected behavior of boost::asio::co_spawn (I did check the docs 1.78.0...), but if i call (e.g. co_spawn(ctx, ..., detached)) from

Performance problems with the C++20 spaceship operator?

Since C++20 the standard library uses the spaceship operator to implement comparison for strings and vectors (according to this video). I am worried that this c

bad_alloc when attempting to print string that was assigned to member of $$ struct

During our compiler's intermediate code generation phase, and more specifically while testing the arithmetic expressions and assignment rules, I noticed that al

Why does string not work here while char const* does?

Why does string not work here when I catch an error, and char const* does? What is the difference between the two? try { throw "connection fail"; } catch(

Holder class (Having some objects references) compile error: 'Can not be referenced -- it is a deletted funciton'

I need a "holder" class. It is supposed to store objects references. Like: holder.A = a; // Gets a reference! Sample code bellow including the compiler error: c