Recent questions tagged C++

0 votes

1.1k views

1 answer

c++ - std::next with n > std::distance(it, c.end())

I do not want to use std::distance because it will calculate whole distance from my iterator to the end. ... should write my own nextIfPossible? See Question&Answers more detail:os...

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

0 votes

1.4k views

1 answer

c++ - llinking @_Znam and @_Znwm

I'm new to c++ programming and currently working on an llvm front-end development project. When I link the ... declare noalias i8* @_Znwm(i64) See Question&Answers more detail:os...

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

0 votes

914 views

1 answer

c++ - Cpp uint32_fast_t resolves to uint64_t but is slower for nearly all operations than a uint32_t (x86_64). Why does it resolve to uint64_t?

Ran a benchmark and uint32_fast_t is 8 byte but slower than 4 byte uint32_t for nearly all operations. If this is ... Edit 6: Added CPU info. See Question&Answers more detail:os...

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

0 votes

1.0k views

1 answer

c++ - SDL_Window not displayed in windowed mode in macOS

Running the following code, I'm not able to view a window unless I set SDL_WINDOW_FULLSCREEN in SDL_CreateWindow. With any ... (); return 0; } See Question&Answers more detail:os...

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

0 votes

1.0k views

1 answer

c++ - What is the expected input type of FindFirstFile?

I'll start by saying I know basically nothing about wide strings and Unicode support. I let QString and ... that FindFirstType will accept? See Question&Answers more detail:os...

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

0 votes

919 views

1 answer

c++ - Using functions that return placeholder types defined in another translation unit

I'm having some trouble understanding how the C++14 extension of the auto type-specifier described in N3638 can ... passing it to a function? See Question&Answers more detail:os...

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

0 votes

1.1k views

1 answer

c++ - Ternary operator

Is there any logical reason that will explain why in ternary optor both branches must have the same base type or be ... ? left() : right(); See Question&Answers more detail:os...

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

0 votes

1.1k views

1 answer

c++ - Qt Creator how to run SUBDIRS projects

I've been using Qt Creator for a while now and my project is getting large enough that I'd like to ... on this would be greatly appreciated. See Question&Answers more detail:os...

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

0 votes

959 views

1 answer

c++ - how to change the value of std::priority_queue top()?

When using std::priority_queue top() it returns a constant reference. So is there a way I can both take advantage ... change the value of top()? See Question&Answers more detail:os...

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

0 votes

1.0k views

1 answer

c++ - Direct Initialization vs Copy Initialization for Primitives

When initializing primitive types like int or pointers one can use either copy-initialization or direct- ... than technical implementation. See Question&Answers more detail:os...

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

0 votes

859 views

1 answer

c++ - Calling a base class method in a template virtual class hierarchy

Let's say I have the following class hierarchy: template< class T > class TestBase { public: virtual T ... without resorting to -fpermissive? See Question&Answers more detail:os...

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

0 votes

1.0k views

1 answer

c++ - UAC prompt elevation - how does it work?

Windows displays UAC prompts on the "secure desktop" when certain security-related operations need to be performed. There' ... any of my code. See Question&Answers more detail:os...

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

0 votes

909 views

1 answer

c++ - OpenGL - Rotate a 'Curve' About the Y-Axis

As per my question on Math Stackexchange: I am working on a project for my 3D Graphics class. The project is ... theta; } glutSwapBuffers(); } See Question&Answers more detail:os...

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

0 votes

1.0k views

1 answer

c++ - how to make std::function instance

In C++0x, we use use std::function like the following: int normal_function() { return 42; } std::function ... facility? Can we implement it? See Question&Answers more detail:os...

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

0 votes

891 views

1 answer

c++ - C++17 template deduction guide not used for empty parameter set?

Consider the following reduced example which can also be viewed at https://godbolt.org/g/Et56cm: #include <utility ... am I missing something? See Question&Answers more detail:os...

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

0 votes

1.1k views

1 answer

c++ - PrintWindow and BitBlt of hidden windows

My program is taking screenshots of other application windows to automate some tasks on them. Those windows can ... is appreciated, thanks. See Question&Answers more detail:os...

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

0 votes

946 views

1 answer

c++ - How to load RSA key pair without p, q, etc

I'm trying to find a way of loading RSA key pair to Openssl using only n, e, d. According to the ... them directly into the RSA structure? See Question&Answers more detail:os...

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

0 votes

952 views

1 answer

c++ - How do I compile a dll with R and RCPP?

I have written a .cpp file and I want to compile it to a .dll for use with R and RCPP. (without using ... prompt. What should I be doing? See Question&Answers more detail:os...

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

0 votes

1.0k views

1 answer

c++ - /boost/lockfree/queue.hpp: error: static assertion failed: (boost::has_trivial_destructor<T>::value)

I'm trying to substitute boost::lockfree::queue for std::queue in this file https://github.com/zaphoyd/ ... server::message_ptr msg; }; See Question&Answers more detail:os...

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

0 votes

903 views

1 answer

c++ - Implicit cast from function to function pointer?

I have a function that accepts as an argument a function pointer. Surprisingly, I can pass in both a ... from functions to function pointers? See Question&Answers more detail:os...

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

0 votes

898 views

1 answer

c++ - How can I perform Template Matching process in SUB-IMAGE extracted from ORIGINAL-IMAGE and Display the results in Original Image

One whole day I have tried a lot to get all the related matches (with matchtemplate function) in sub-Image ... would be appreciated greatly!! See Question&Answers more detail:os...

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

0 votes

942 views

1 answer

c++ - wxTaskBarIcon in Ubuntu 12.10

I built wxWidgets 2.9.3 (for the moment I must stick to this version) under Ubuntu 12.10 and I can't ... updates at least once a week. See Question&Answers more detail:os...

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

0 votes

853 views

1 answer

c++ - Are pointers to allocated memory outside object's lifetime "invalid pointer[s]" or "pointer[s] to an object"?

C++17 (draft N4659) [basic.compound]/3 says: Every value of pointer type is one of the following: a pointer ... to which object do they point? See Question&Answers more detail:os...

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

0 votes

1.0k views

1 answer

c++ - Is deleting copy and move constructors/assignment operators in base class enough?

If I have an abstract base class and I want to make all derived classes noncopyable and nonmovable is it ... DerivedClass &) = default; See Question&Answers more detail:os...

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

0 votes

1.1k views

1 answer

c++ - Parallelizing a for loop using openmp & replacing push_back

I'd like to parallelize the following piece of code but am new to openmp and creating parallel code. std::vector ... to anyone who can help. See Question&Answers more detail:os...

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

0 votes

1.0k views

1 answer

c++ - When are const volatile objects necessary?

When are const volatile objects necessary in C++? Note: I do understand the need for pointers to const ... are these necessary or useful? See Question&Answers more detail:os...

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

0 votes

991 views

1 answer

c++ - The most efficient way to reverse a number

I am looking for an efficient algorithm to reverse a number, e.g. Input: 3456789 Output: 9876543 In C++ ... there is no leading zeros problem. See Question&Answers more detail:os...

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

0 votes

1.1k views

1 answer

c++ - Python method to boost function

I have a method exported to Python using boost python that takes a boost::function as an argument. From what ... functions as a boost::function? See Question&Answers more detail:os...

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

Categories

Just Browsing Browsing

Most popular tags