Recent questions tagged C++

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c++ - passing functor as function pointer

I'm trying to use a C library in a C++ app and have found my self in the following situation (I know my ... pointer to pass to the C function? 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++ - "IF" argument evaluation order?

if(a && b) { do something; } is there any possibility to evaluate arguments from right to left(b -> a)? ... evaluation order? (i'm using VS2008) 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++ - Difference in behavior while using dynamic_cast with reference and pointers

I was checking the behavior of dynamic_cast and found that when it fails, std::bad_cast exception is thrown only ... why there is a difference? 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++ - C++11 static_assert and template instantiation

In C++11, should the operation of static_assert within a template depend on whether that template has been ... hand, gives no message. 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++ - Most efficient/elegant way to clip a number?

Given a real (n), a maximum value this real can be (upper), and a minimum value this real can be (lower), ... why I'm putting this out there..! 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 portable is end iterator decrement?

Just encountered decrement of end() iterator in my company source codes and it looks strange for me. As far as I ... .end(); Thanks in advance. 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 automatically register a class on creation

I was wondering whether a design pattern or idiom exists to automatically register a class type. Or ... not actually implementing animals. 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++ - Search for a struct item in a vector by member data

I'm very new to c++ and I'm trying to find a way to search a vector of structs for a struct with a certain ... Is there a simple way to do 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++ - Difference between using character pointers and character arrays

Basic question. char new_str[]=""; char * newstr; If I have to concatenate some data into it or use ... some nice exhaustive content/material? 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 safe way to fill multidimensional array using std::fill?

Here is what I am using: class something { char flags[26][80]; } a; std::fill(&a.flags[0][0], &a.flags ... that I am using this inside a class.) 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++ - C++11: Compile-time Array with Logarithmic Evaluation Depth

One way to implement a C++11 array that has its elements initialized by a function of their index calculated ... avoid the default depth limit) 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 the uses of std::chrono::high_resolution_clock?

At first I thought it can be used for performance measurements. But it is said that std::chrono:: ... ::high_resolution_clock be used for? 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++ - Prefix/Postfix increment operators

I'm wanting to make sure I understand pass-by-value vs pass-by-reference properly. In particular, I'm looking at ... .are a and b now aliases? 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++ - Populate An Array Using Constexpr at Compile-time

I would like to populate an array of enum using constexpr. The content of the array follows a certain pattern ... would be appreciated. Thanks, 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++ - Calculating the Amount of Combinations

Cheers, I know you can get the amount of combinations with the following formula (without repetition and order is ... party "bigint" -libraries? See Question&Answers more detail:os...

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

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275 views

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c++ - Sorting two corresponding arrays

I have this code here that has two arrays. It sorts arr[], so that the highest value will be in index 0. Now ... << endl; system("pause"); } 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++ - delete[] an array of objects

I have allocated and array of Objects Objects *array = new Objects[N]; How should I delete this array? Just ... to force the code to 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++ - Uninitialized pointers in code

I am learning C++ and I came to know that pointers if left uninitialized could point to random locations ... possible give some examples also. 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++ - Should a move constructor take a const or non-const rvalue reference?

In several places I've seen the recommended signatures of copy and move constructors given as: struct T { T ... returning things that are const? 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 is partial specialization of a nested class template allowed, while complete isn't?

template<int x> struct A { template<int y> struct B {};. template<int y, int unused> struct C {} ... depend on the outer template parameter. 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 do you insert the value in a sorted vector?

ALL, This question is a continuation of this one. I think that STL misses this functionality, but it just my ... Any help would be appreciated. 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 does malloc understand alignment?

following excerpted from here pw = (widget *)malloc(sizeof(widget)); allocates raw storage. Indeed, the malloc ... alignment of the custom type? 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 do I use unique_ptr for pimpl?

Here is a simplification of what I'm seeing when I try to use unique_ptr for pimpl. I chose unique_ptr because I ... the Help dtor wrong? Argh! 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++ - Writing a simple equation parser

What sorts of algorithms would be used to do this (as in, this is a string, and I want to find the ... I deal with so many nested parenthesis? 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 read / write a struct in Binary Files?

I am facing a small problem. I have a struct, which has a vector. Note that the vector is dynamic per ... not use any third-party libraries. See Question&Answers more detail:os...

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

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450 views

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c++ - GIF animation in Qt

I have used QGraphicsView, QGraphicsScene classes in order to show a picture in a widget like this: m_Scene-> ... animation in the same scene? See Question&Answers more detail:os...

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

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243 views

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c++ - Reading line from text file and putting the strings into a vector?

I am trying to read each line of a textfile which each line contains one word and put those words into a vector. ... cout<<DataArray[0]<<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++ - Compiling libjpeg

Is there anyone who succeed to include libjpeg in some compiler? I tried everything: Dev C++, VS10, CodeBlocks ... . Thank you in advance. See Question&Answers more detail:os...

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

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