C++ - Страница 1243

I have downloaded and extracted the latest opencv-4.9.0 and installed latest code blocks-20.03.
When I tried to use the opencv functions like waitKey(), imread, imshow() to load an image and to display, after including the paths in the build...

I'm new to asio and was follwing a tutorial. After sending a pretty basic http get request to example.com there is no response.
#include
#include
#include
#include

#define ASIO_STANDALONE

int main(){
asio::error_code ec;
asio::io_context...

I am new to both visual studio 2019 and github. I am attempting to obtain a code from the github cloud and run it on my laptop.
Currently I have been able to clone the github repo for the source code and create a new branch. However the github repo...

I recently discovered the ranges stdandard library and encountered a strange behavior. When chaining multiple range adaptors, I can't chain after using std::ranges::views::join :
vec | std::ranges::views::slide(2) | std::ranges::views::join
works...

With respect to the following code:
static constexpr auto v = {0, 1, 2, 3, 4, 5};
for (int n : v | std::views::drop_while([](int i) { return i < 3; }))
std::cout

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I've always been amazed at how much much much faster things become if you manage to rewrite code that loops though your ndarray and does something, with numpy functions that work on the whole array at once. I'm looking for something similar in node....

I'm struggling to use isio::strand on coroutine.
I need to send request to a server which is mainly asynchronous, for each request I send I would like to wait to receive the ACK before performing the next request.
I have tested the following...

I would like to optimize this cycle because my performance are so bad. For each iteration I call the kernel that just separate nodes in two lists, the list that contain the nodes that have at least an edge pointing to the list of current leaves, and...

Should a class with its ctor =delete d be prefered if all its functions and variables are public and static , or should this be made as a namespace instead? Which, in terms of the following code, should A or B be preferred?
// Snippet A
class Foo...

i am solving a leetcode problem, where two sorted linked lists are given and we have to merge them and return a sorted list. I have not yet learned merge sort, and tried this question with brute force approach. I want to know why am i getting...

Can someone please explain why I should use strstr or string find() ? Which one is faster, at where ?

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#include
#include
#include
#include
#include
#include
using namespace std;

// Enum for the types of rooms in the dungeon
enum class RoomType { Empty, Monster, Treasure };

class Room {
public:
RoomType type;
vector connectedRooms;

//...

Was studying C++ when this answer came across. It suggests a class with purely static members with instantiation intentionally disabled.
But if the class shall not be instantiated, is there a reason namespace is not used instead? And if so or not,...

I have two classes: a Parent class and a Child class (inheriting from the Parent class). I would like to know if it is possible to cast/transform a Child** to a Parent** with reinterpret_cast or something else. Is such a thing possible?
Below is a...

I'm trying to optimize my 3D rendering OpenCL code. Currently, I render a 3D triangle by dividing its bounding box into 2x2 tiles and doing necessary computations for each pixel inside the tile. This turned out to be slightly faster than giving each...

Is it possible to create an ImGui screen without a background or window?
It would just be the ImGui window that can be dragged across the screen.
It would looks something like this, but instead of a blue background, you'd just see the application...

so I'm trying to compile a project of OpenFrameworks v11.2 with VS Community 2017, and I get the next error:
clientcore\windows\advcore\ctf\uim\tim.cpp(800)\MSCTF.dll!7613246A: (caller: 7612DC20) LogHr(1) tid(2818) 8007029C An assertion failure has...

I would like to have objects add a pointer pointing to themselves into a map which is a member of another class.
Here is what I have so far:
//entitymanager.h
//inside the public part of the entitymanager class
std::map AllMapEntities;

//in...

I just started learning qt widgets and C++ in general, so I don't understand a lot. I created a regular project, made a full-screen view, created a scene inside it, and set a square inside the scene. I wanted to set view, scene, rect to different...

I have this code, but I need help to use OpenMP #pragma s to increase its speed. I want to parallelize the for loops over variables i and j . The values of n and m can be much larger, too. For example, n = 1000 , m = 500 .
My code:
for (int i = 0;...

for (int nu = 0; nu < 20; nu++) {
for (int i = 0; i < n; i++) {
for (int j = 0; j < m; j++) {
double matrixPtr = matrix .first;
double matrixPtrSecond = matrix .second;
double localReS1 = 0.0;
double localImS1 = 0.0;
for (double theta = 0; theta < 2...

I want to list FTDI ports with their description, here is my program:

#include
#include ftd2xx.h

int main( int argc, char* argv[] )
{
DWORD numDevs = 0, i = 0;
FT_DEVICE_LIST_INFO_NODE *ftDevList = NULL;
FT_STATUS ftStatus;

/* Get the number...

I'm trying to understand the basics of C++ classes and the different forms of copying a class to another one, I made a simple class that use a table as a stack and i created simple function for stacking/unstacking integers
pileInt.h :
class...

The following C++ code does not compile with VS2015:
#include
#include

void main()
{
const time_t t = std::time(nullptr);

std::tm tm = {};

std::localtime_s(&tm, &time);
}

The error messages are:
Microsoft (R) C/C++ Optimizing Compiler...

How we can render or draw texts, numbers and characters in openGL and Qt opengl widget?
is there any step by step guide?
I tried renderText method but it seems that this method is no longer supported.
and freetype is mentioned in some sources but i...