Recent questions tagged C++

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c++ - Can I use placement new to reset an object within a shared_ptr?

Let's say I have a class. class BigData {...}; typedef boost::shared_ptr<BigData> BigDataPtr; ... object without any additional allocations? 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 include .obj files into the project

I have the following question: I was given the task - to build an application. There was a ready file counter ... should the file itself go? 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++ - Is it well defined to reference a variable before it's constructed

This is similar in spirit to a question that was asked and answered for c. The comments there implied that a ... this appears to work as well. 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++ - What algorithm should I use for high-performance large integer division?

I am encoding large integers into an array of size_t. I already have the other operations working (add, subtract, ... one beats me to it. 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++ - std::isinf does not work with -ffast-math. how to check for infinity

Sample code: #include <iostream> #include <cmath> #include <stdint.h> using namespace std; static bool ... improvement opportunity with isNaN 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++ - Enable method based on boolean template parameter

I want to implement a private function based on a boolean template parameter. Something like that: #include ... desired behavior with enable_if? 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++ - Get a font filename based on the font handle (HFONT)

I came across a situation where we needed to know the filename of a font currently in use by a QFont. ... ); FindFontFileName(font.handle()); 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++ - What does add_lvalue_reference do?

I have this class that makes a path for a montecarlo simulator where it takes creates paths of integers from ... so any insight is 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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c++ - Reading from serial port with Boost Asio

I'm want to check for incoming data packages on the serial port, using boost.asio. Each data packet will start ... want the function to block... 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++ - Calling WSAGetLastError() from an IOCP thread return incorrect result

I have called WSARecv() which returned WSA_IO_PENDING. I have then sent an RST packet from the other end. ... retrieving a completion packet. See Question&Answers more detail:os...

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

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314 views

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c++ - How to set Visual Studio 2012 RC Compiler for Qt instead of MinGW?

Windows 8 x86; Qt 4.8.2; Visual Studio Ultimate 2012 RC See Question&Answers more detail:os...

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

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314 views

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c++ - SFINAE : Delete a function with the same prototype

I wonder what is the difference between this code that works : #include <type_traits> #include <iostream> template<typename ... <T> = true ? 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 isn't my new operator called

I wanted to see that a dynamically loaded library (loaded with dlopen etc.) really uses its own new an ... program. Thanks to Employed Russian! See Question&Answers more detail:os...

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

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398 views

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c++ - Getting a unique_ptr out of a priority queue

I am maintaining a set of unique_ptr instances in a priority_queue. At some point, I want to get the first ... or am I missing something? 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++ - Avoiding dynamic_cast/RTTI

I was recently working on a piece of C++ code for a side project (the cpp-markdown library, for the curious ... too much about trivialities. :-) See Question&Answers more detail:os...

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

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172 views

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c++ - Destructor not invoked when an exception is thrown in the constructor

Why is the destructor not invoked in this code? #include <boost/scoped_ptr.hpp> #include <iostream> class MyClass ... instance of 'int' Aborted See Question&Answers more detail:os...

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

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221 views

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c++ - Getting return value from a boost::threaded member function?

I have a worker class like the one below: class Worker{ public: int Do(){ int ret = 100; // do stuff ... of Worker::Do? Thanks in advance. See Question&Answers more detail:os...

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

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369 views

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c++ - VS2012 : Error with unit test : Assert::AreEqual( object, object ) didn't work

I come to you for a strange problem when I use the Visual Studio Native Unit Test on VS 2012. I've a ... english, is not my native language. See Question&Answers more detail:os...

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

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498 views

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c++ - __attribute__((init_priority(X))) in GCC

I'm using __attribute__((init_priority(X))) in GCC like this: Type1 __attribute__ ((init_priority (101))) ... big project from Visual Studio. See Question&Answers more detail:os...

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

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270 views

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c++ - Extract the return type of a function without calling it (using templates?)

I'm looking for a way in C++ to extract the return type of a function (without calling it). I presume this ... a solution so far. 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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250 views

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c++ - Why doesn't auto_ptr construction work using = syntax

I ran into a compiler error that didn't make much sense to me: #include <memory> using namespace std; auto_ptr<Table> ... () : _M_ptr(__p) { } See Question&Answers more detail:os...

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

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280 views

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c++ - Const reference to temporary

After reading this article on Herb Sutter's blog, I experimented a bit and ran into something that puzzles me. ... have an explanation for this? See Question&Answers more detail:os...

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

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199 views

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c++ - On what architectures is calculating invalid pointers unsafe?

int* a = new int[5] - 1; This line by itself invokes undefined behavior according to the C++ standard ... C++ compilers have this issue. See Question&Answers more detail:os...

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

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348 views

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c++ - How do you erase *AND CONTINUE* using a std::reverse_iterator?

I've been up and down stackoverflow and even the very, very nice Dr. Dobbs article but I can't find a ... an answer to this specific question. See Question&Answers more detail:os...

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

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312 views

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c++ - Build external library only once with CMake

My C++ projects includes the source code of a third-party library (currently as a git submodule). This library ... not cleaned by make clean ? See Question&Answers more detail:os...

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

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636 views

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c++ - Get derived type via base class virtual function

I am trying to get the derived type of an object via a base class virtual function. I have written this, which ... to my problem. Thanks again! See Question&Answers more detail:os...

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

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480 views

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c++ - Pointer to const char vs char array vs std::string

Here I've two lines of code const char * s1 = "test"; char s2 [] = "test"; Both lines of code ... which situations should I use which approach? 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++ - Running a process with lowest possible privileges in winapi

I am writing something similar to the http://ideone.com/. Currently I am running user processes with CreateProcess ... with snemarch's links. See Question&Answers more detail:os...

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

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