C++ - Страница 1254

I was playing with this code to check if an integer is a power of 4:

// C++ version bool is_pow_4(unsigned a) { return (std::popcount(a) == 1) && (std::countr_zero(a) % 2 == 0); } // C version int is_pow_4(unsigned a) { return...

Context:
We've recently upgraded from gtk2 to gtk3 and for this had to get rid of GtkGLExt as our OpenGL context as it does not support gtk3. Doing so we've decided to use wglContext and setting the render context ourself. We develop a heavily...

I'm reading a C++ function that handles timestamps, and there's an expression like this:

t % (60 * 60) % 60 I thought this expression was strictly equivalent to:

t % 60 However, when I entered this code into godbolt.org, I found that gcc did not...

I was wondering that if we run multiple calls of async_resolve than in practice the io_context doesn't run more than one request at the time due to a known limitation.

Here's a sample example where I'd expect that each resolve request will yield...

I am currently facing a problem of the HANDLE returns NULL from network located printers.

//NOTE:szDriver is the driver location //my device name = \\somelocation\HP Color LaserJet CP3505 PCL 6 , HANDLE hDC; hDC =...

Whenever I see examples of union, they are always different types. For example, from MSDN:

// declaring_a_union.cpp union DATATYPE // Declare union type { char ch; int i; long l; float f; double d; } var1; // Optional declaration of union variable...

I have the following task:

Develop a hotel reservation system to allow customers to book rooms and control demand for hotel owners. Your program should handle the following events:
BOOK time hotel_name client_id room_count — Book by the client...

I have the following member function in a class

class cls { ... template bool func(...) { // Do something depending on } ... } I want to change func to be private and instead have only the relevant instantiations of func public, e.g something like...

I read and load the code from a open source in Visual Studio 2022 community. There is a statement:

auto param_state = state_.find(c10::guts::to_string(p.unsafeGetTensorImpl())); I got an error:

Error (active) E0135 namespace c10::guts has no...

I would like to specialize a function template such that the return type changes depending on the type of the template argument.

class ReturnTypeSpecialization { public: template T Item(); }; // Normally just return the template type template T...

I have a framebuffer object (FBO) that I create like so

glGenFramebuffers(1, &m_FBO); glBindFramebuffer(GL_FRAMEBUFFER, m_FBO); auto& window_descriptor = m_WindowManager->GetDescriptor(); glGenTextures(1, &m_FBO_texture);...

Is there standard way to include a references section for a doxygen docstring in C++? For example, for documenting references that influenced the implementation, the python library statsmodels sometimes includes a References section in the docstring...

I noticed that libstdc++ often uses a base class for the implementation of standard allocator-aware containers. Especially, some basic functionalities are implemented in a base class that is inherited by the correponding container class, like...

I am trying to set up the Hello World example from the FastDDS tutorial here:

When I run the publisher and subscriber (separate terminals), they can't find each other. I never get the Publisher matched and Subscriber matched lines.

What can I...

I am writing a binary search tree (BST) with bidirectional iterator. To present .end() I have fake node , that is the rightest son of the tree. I have problem with extract: my code works incorrectly whenever it gets to fake node . I made a flag in...

#include // maximum of two values of any type (call-by-reference) template T const& max (T const& a, T const& b) { return b < a ? a : b; } // maximum of two C-strings (call-by-value) char const* max (char const* a, char const* b) { return...

I'm trying to build a dll for the microsoft PICT model:

My objective is to be able to call the model API from another code project.

I modified the makefile in order to produce a dll on windows instead of a so Here are the changes:
Added...

I try to create a socket communication for the FastPIR protocol.

The client side have a PIRQuery query which is a std::vectorseal::Ciphertext type that want to send it to the server.

How can I send the query to the server ? and how the server...

I'm trying to check if all values in nested vector are same/unique. I wrote this program (simplified, but same error):

godbolt link

#include #include #include #include auto main() -> int { std::vector vectors_of_ints { {1, 2, 3}, {4, 5, 6} };...

I have a struct with a union inside. How can I make a get_data() function that should return a bool if(value == input_value::_bool).

enum class input_value { _bool, _1D, _2D, _3D, }; struct input_action { union input_action_data { bool boolean;...

I'm porting existing project code from x64 Linux to equivalent ARM64 machine. However, the function snprint has different outputs on the two platforms. I've reduced my problem down to this small function:

#include #include int main() { const char*...

Recently I created class Square:

=========header file======

class Square { int m_row; int m_col; public: Square(int row, int col): m_row(row), m_col(col) }; ==========cpp file======

#include Square.h Square::Square(int row, int col) { cout...

I have only been working with C++ for a year now and I am hoping to gain a better understanding of abstraction with my current project. I created a Black Jack card game from my book 'Beginning C++ Through Game Programming'. The game works, but I am...

I use libarchive to create a archive, and the source is a directory, I need create the archive with the same directory tree of the source directory, so I use the archive_read_disk_open and archive_read_disk_descend, but when i create a file with...

I want to add a simple python interface on a large c++ project so that I can call some c++ functions using python. It is a large c++ project and the structure is like

FastBN -src // many source files inside -include // many header files inside...