Recent questions tagged C++

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c++ - How does shared_ptr work in if condition

In C++, I can write something like: shared_ptr<A> a_sp = someFunctionReturningSharedPtr(); if (a_sp) { cout < ... converts it to boolean value? 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++ - can we pass arrays as arguments to functions by this syntax, under upcoming c++0x standards?

suppose we have following function: void someFunction(int * araye){ for (int i=0;i<5;i++) cout <<araye[ ... approach to use that expression? . 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 standard container iterators don't overload `->*`?

Apparently ->* doesn't work automagically if you overload ->, and has to be overloaded manually. Why iterators for ... line doesn't compile. } 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 possible to move an item out of a std::set?

If I have an object that only allows move-only semantics - is it possible to move items from a set? I can't seem to find a way to do 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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c++ - template aliases and sfinae

In the case of a substitution failure involving a template alias (e.g. a template alias on a missing member typename, ... and why ? 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++ - Are there any drawbacks to using -O3 in GCC?

I've been a Software Engineer for 13 years in various languages, though I'm just now making my way into ... html before I posted this 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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c++ - Why does a variable become 'const' when I use a [=] capture (using Lambda class)?

Premise #1: I have already solved the error, but I didn't deeply understand the cause of the compiler error. ... why I received that error. 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++ - Could multiple proxy classes make up a STL-proof bitvector?

It's well known that std::vector<bool> does not satisfy the Standard's container requirements, mainly ... defined conversion per argument). 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 catch all types of exceptions in one catch block?

In C++, I'm trying to catch all types of exceptions in one catch (like catch(Exception) in C#). How ... one catch divide-by-zero exceptions? 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++ - Class component order of initialisation

class D: A { B obj; C obj2; } What order of construction here is guaranteed? I know that D will be ... or don't have a default 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++ - What's the best way do determine if an HWND represents a top-level window?

Is it to check for the WS_CHILD bit: LONG style = GetWindowLong(hwnd, GWL_STYLE); int isTopLevel = !(style ... only existing Windows API code. 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 is the range of OpenGL texture ID?

I have an object which owns a property Texture_ID. I need to initialize the value for Texture_ID in constructor, so ... of this range. Any idea? 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 enable all compiler warnings in CLion?

I want to see all compiler warnings in CLion. I don't want them treated as errors, but I want to inspect all of them. How can I do 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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c++ - Programmatically check whether my machine has internet access or not

How can I programmatically check whether my machine has internet access or not using C/C++, is it just a matter ... like: I am using Windows 7. 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++ - Make Qt application not to quit when last window is closed

I've created a Qt application that acts mostly as a daemon, but occasionally shows a dialog. Now, I know ... the behavior of my application? 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++ - Can we use wmain() with Unix compilers or it'll work only on Windows?

Can we use the wmain() function with Unix compilers or it'll work only on/for Windows? 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 template function without <>; type inference

If I have a function template with typename T, where the compiler can set the type by itself, I do not have ... inference" possible in C++0x? 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++ - Using boost::accumulators, how can I reset a rolling window size, does it keep extra history?

I am looking at the boost::accumulator framework, specifically a couple of the rolling_window calculations. #include < ... for the extra values? 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::array<T> initialization

A std::array<T> is essentially a C-style array wrapped in a struct. The initialization of structs requires ... compared to the first approch? 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 are implicitly and explicitly deleted move constructors treated differently?

What is the rationale behind the different treatment of implicitly and explicitly deleted move constructors in the C++11 ... s move return 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++ - How do I get the copy constructor called over a variadic constructor?

In the following code, the variadic constructor is called twice. How can I get the copy constructor to be ... want the copy 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++ - Floating-point types as template parameter in C++20

According to cppreference C++20 now supports floating-point parameters in templates. I am, however, unable to ... briefly explain that instead. 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++ - Function-style cast vs. constructor

I learned that in C++, typedef foo* mytype; (mytype) a // C-style cast and mytype(a) // function- ... . interpreted as a function-style cast? 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 does the compiler select the base class constructor inside the template argument list?

Follow-up question to this one. Basically, in the following code, why does the compiler think that the B inside A<B> ... C++ spec. What is 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++ - warning: specialization of template in different namespace

With the following piece of code I get the warning: warning: specialization of template<class _Iterator> struct std:: ... clang++ doesn't ). 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 (or will be) the use of familiar template syntax in lambda expressions allowed?

C++14 introduced generic lambdas. While skimming through the related proposals I found N3418 by Faisal Vali, ... lambdas into the 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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c++ - How to split a std::string into a range (v3) of std::string_views?

I need to split a std::string at all spaces. The resulting range should however transform it's element to ... :transform(std::string_view); } 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++ - Method for solving error: "cannot instantiate abstract class"

I find one of the most time-consuming compiler errors for me is "cannot instantiate abstract class," since the ... How do you solve these? See Question&Answers more detail:os...

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

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