Recent questions tagged c++

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c++ - invalid conversion from 'const char*' to 'char*'

Have a code as shown below. I have problem passing the arguments. stringstream data; char *addr=NULL; ... need to change any initialization. See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - Confused about std::runtime_error vs. std::logic_error

I recently saw that the boost program_options library throws a logic_error if the command-line input was un- ... model of exception typing? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - Why do C++17 structured bindings not use { }?

I found the original proposal for *C++ structured bindings here. It proposes a way to easily bind multiple ... problem with curly braces here? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - Measuring text width in Qt

Using the Qt framework, how do I measure the width (in pixels) of a piece of text rendered with a given font/style? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - New iterator requirements

I noticed that most if not all containers now require their ::iterator type to satisfy ... and LegacyRandomAccessIterator)? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - How can I iterate through a string and also know the index (current position)?

Often when iterating through a string (or any enumerable object), we are not only interested in the current ... track of the current index? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - Where to use std::variant over union?

Please explain what is the difference between union and std::variant and why std::variant was introduced into the ... over the old-school union? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - How to emplace object with no-argument constructor into std::map?

I want to emplace an object into a std::map whose constructor does not take any arguments. However, std: ... zero arguments to the constructor? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - Why do I need to explicitly write the 'auto' keyword?

I am moving towards C++11 from C++98 and have become familiar with the auto keyword. I was wondering ... explicitly declaring a variable auto? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - Why doesn't 'd /= d' throw a division by zero exception when d == 0?

I don't quite understand why I don't get a division by zero exception: int d = 0; d /= d; I expected to ... by zero exception when d == 0? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - Why is std::ssize() introduced in C++20?

C++20 introduced the std::ssize() free function as below: template <class C> constexpr auto ssize(const C& c) - ... ssize() introduced in C++20? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - How to use NDK in android project?

I need to use some native c/c++ in my project, so I need to use the NDK. Is there an easy way to set it up in eclipse? Thanks. See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - 3D Line Segment and Plane Intersection

I'm trying to implement a line segment and plane intersection test that will return true or false depending on whether ... true... any ideas? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - OpenGL: How to render perfect rectangular gradient?

I can render triangular gradient with simply just one triangle and using glColor for each corner. But how to ... images were broken(removed). See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - Factory pattern using variadic template?

I have an abstract class template <class T> struct A { /* virtual methods */ }; and several concrete ... to make this shorter appreciated. See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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203 views

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c++ - Cube sphere intersection test?

What's the easiest way of doing this? I fail at math, and i found pretty complicate formulaes over the internet.. ... in the x,y,z axises See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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590 views

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c++ - How to handle EINTR (interrupted System Call)

My user-space application sometimes blocks after receiving an EINTR-Signal, somehow. What I recorded with strace: ... to user space? thanks See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - Why is the derived class's destructor invoked on a const reference to the base class?

In GMan's answer here, the destructor of the restore_base class isn't virtual, so I keep wondering how exactly ... Anyone care to enlighten me? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - Sorting 64-bit structs using AVX?

I have a 64-bit struct which represents several pieces of data, one of which is a floating point value: struct ... the float member MyStruct::f? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - CGAL - Retrieve Vertex Index After Delaunay Triangulation

I am computing the 2D delaunay triangulation of a few thousand points. Each point has more data associated with it beyond ... 1 3 4 Vertex 0: 1 See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - How do a specify a library file dependency for qmake in Qt?

Have a SomeLib.pro file that contains: CONFIG += debug TEMPLATE = lib TARGET = SomeLib .. Then in a dependent ... if I touched SomeLib in qmake? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - Heap fragmentation and windows memory manager

I'm having trouble with memory fragmentation in my program and not being able to allocate very large memory ... to allocate objects? Thanks. See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - Designing a thread-safe copyable class

The straightforward way to make a class threadsafe is to add a mutex attribute and lock the mutex in the accessor methods ... S.getA(); } }; See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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414 views

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c++ - Need help in reading JPEG file using libjpeg

I followed the example code in the libjpeg example file, however I was not able to read the image data. I have ... a memory problem. Any ideas? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - DXGI Desktop Duplication: encoding frames to send them over the network

I'm trying to write an app which will capture a video stream of the screen and send it to a remote client. ... to stream to a mobile platform. See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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353 views

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c++ - Are volatile reads and writes atomic on Windows+VisualC?

There are a couple of questions on this site asking whether using a volatile variable for atomic / multithreaded access ... , links, test-cases! See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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194 views

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c++ - Enabling `-std=c++14` flag in Code::Blocks

I have installed Code::Blocks for Windows and want to compile C++14 code like generic lambdas but the binary ... 14 flag for Code::Blocks? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - shared library address space

While I was studying about shared library I read a statement Although the code of a shared library is shared ... help me understand. Thanks! See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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