Recent questions tagged C++

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c++ - Can multithreading speed up memory allocation?

I'm working with an 8 core processor, and am using Boost threads to run a large program. Logically, the ... to allocate memory in parallel? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - RAII wrapper for OpenGL objects

I want to write a simple RAII wrapper for OpenGL objects (textures, frame buffers, etc.) I have ... anyone suggest more elegant solution? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - Why GCC does not use LOAD(without fence) and STORE+SFENCE for Sequential Consistency?

Here are four approaches to make Sequential Consistency in x86/x86_64: LOAD(without fence) and STORE+MFENCE ... for std::memory_order_seq_cst? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - How to break shared_ptr cyclic reference using weak_ptr

I have read that weak_pointers can be used to break cyclic references. Consider the following example of a cyclic ... be the correct approach ? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - Interpolate from one color to another

I am trying to get an interpolation of one color to another shade of the same color. (for eg: sky blue to ... Any ideas how to go about this? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - How to convert RGB -> YUV -> RGB (both ways)

I want a pair of conversion algorithms, one from RGB to YUV, the other from YUV to RGB, that are inverses ... it tricky to define an inverse. See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - Why does the postfix increment operator take a dummy parameter?

Have a look at these function signatures: class Number { public: Number& operator++ (); // prefix ++ ... them with different return types. See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - What are "rvalue references for *this" for?

What are the most typical use cases of "rvalue references for *this" which the standard also calls reference ... this language feature here. See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - Windows Vista/Windows 7 privilege: SeDebugPrivilege & OpenProcess

Everything I've been able to find about escalating to the appropriate privileges for my needs has agreed with my ... Overflow so useful to all! See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - How to change an executable's properties? (Windows)

When I create a .exe, I can right click it and go to properties->details. Then I get a list like: File ... there a way to change the icon?) See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - How to get a list of files in a folder in which the files are sorted with modified date time?

I need to a list of files in a folder and the files are sorted with their modified date time. I am working ... code of how to implement this? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - Who defines C operator precedence and associativity?

Introduction In every textbook on C/C++, you'll find an operator precedence and associativity table such as ... is it defined in Mathematics? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - When do we need to have a default constructor?

My question is simple. When do we need to have a default constructor? Please refer to the code below: class ... be generated by the compiler. See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - Print macro values without knowing the amount of macros

I have code that includes a generated file (I don't know in advance its content), there is just a convention ... to duplicate my code so much See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - "Default member initializer needed within definition of enclosing class outside of member functions" - is my code ill-formed?

#include <utility> struct foo { int x{0}; foo() noexcept = default; void f() noexcept(noexcept(std::declval< ... x will make the code compile. See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - Get Local IP-Address using Boost.Asio

I'm currently searching for a portable way of getting the local IP-addresses. Because I'm using Boost anyway I thought ... ep << std::endl; } See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - Why does not a template template parameter allow 'typename' after the parameter list

Template template typename? When using template template syntax as in template <template <typename> class T>, it ... say anything about this? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - fatal error: Eigen/Dense: No such file or directory

I have installed libeigen3-dev in order to compile programs using Eigen 3. when I include a file, such ... or directory compilation terminated. See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - Understanding the different clocks of clock_gettime()

Hi I wanted to use the clock_gettime() function for measuring the performance of my code. I am unable to ... each of these clocks do? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - Is there a reason declval returns add_rvalue_reference instead of add_lvalue_reference

changing a type into a reference to a type, allows one to access the members of the type without creating an ... , then I'll be satisfied. See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - GCC error with variadic templates: "Sorry, unimplemented: cannot expand 'Identifier...' into a fixed-length argument list"

While doing variadic template programming in C++11 on GCC, once in a while I get an error that says " ... directly. Can anyone confirm this? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - Press Enter to Continue

This doesn't work: string temp; cout << "Press Enter to Continue"; cin >> temp; See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - What is the best way to wait on multiple condition variables in C++11?

First a little context: I'm in the process of learning about threading in C++11 and for this purpose, I ... ::rethrow_exception(exception); } }; See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - Why does Visual Studio not perform return value optimization (RVO) in this case

I was answering a question and recommending return by-value for a large type because I was confident ... had additional constructor parameters. See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - Portable branch prediction hints

Is there any portable way of doing branch prediction hints? Consider the following example: if (unlikely_condition) ... of the conditions? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - Is it valid for a lambda to, essentially, close over itself?

Is this lambda recursion valid? #include <functional> #include <iostream> int main() { std::function<int(int)> g = [&g] ... a scale of 1-10...? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - Is it always the case that sizeof(T) >= alignof(T) for all object types T?

For any object type T is it always the case that sizeof(T) is at least as large as alignof(T)? Intuitively ... both a size and alignment of 16. See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - Do STL maps initialize primitive types on insert?

I have a std::map like this: map<wstring,int> Scores; It stores names of players and scores. When someone ... program it is usually not zero. See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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