Recent questions tagged c++11

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c++11 - C++ constructors: why is this virtual function call not safe?

This is from the C++11 standard sec 12.7.4. This is rather confusing. What does the last sentence in the text ... base of B } -end example ] 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++11 - Does the C++ standard guarantee that a function return value has a constant address?

Consider this program: #include <stdio.h> struct S { S() { print(); } void print() { printf("%p ", ( ... I would like to avoid that if possible. 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++11 - C++ function returning function

Where in the standard are functions returning functions disallowed? I understand they are conceptually ridiculous, ... and third declarators. 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++11 - How to determine what C++ standard is the default for a C++ compiler?

It is frequently mentioned that the -std flag should be used to specify the standard that one wishes to use ... once it has been corroborated. 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++11 - Is it possible to determine the number of elements of a c++ enum class?

Is it possible to determine the cardinality of a c++ enum class: enum class Example { A, B, C, D, E }; ... the cardinality (5 in my example) ? 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++11 - C++ object-pool that provides items as smart-pointers that are returned to pool upon deletion

I'm having fun with c++-ideas, and got a little stuck with this problem. I would like a LIFO class that ... the resource back to the pool. 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++11 - What is the difference between unordered_map::emplace and unordered_map::insert in C++?

What is the difference between std::unordered_map::emplace and std::unordered_map::insert in C++? 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++11 - Const reference VS move semantics

I was wondering in which situations I still need to use const references in parameters since C++11. I don't ... , besides it looks much cleaner. 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++11 - C++ std::unique is not showing what I am expecting from it

I was trying to find if the vector contains duplicates (please don't provide an algorithm to check duplicates.) I came ... nums1 4 3 Nums2 4 4 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++11 - how to customise default Boost xml Serialisation default node naming to make it more readable

The code below generates a xml file but , when it loops theough a map , it always names the map key ... > </Connections> </boost_serialization> 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++11 - Can I tell if a C++ virtual function is implemented

I want to be able to tell at run-time if an instance of a class implements a virtual function. For ... been redefined in a derived class 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++11 - How can I get CodeBlocks to compile with -std=c++0x with gcc?

How can I get CodeBlocks to compile with -std=c++0x with gcc? I would like to see if they treat new features with ... of stuff n C++-0x now. 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++11 - c++: alternative to 'std::is_fundamental'?

In a function within a template class, I'm trying to distinguish between primitive types and others. In c++ 11 ... in earlier versions of c++? 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++11 - Why do Qt's container classes not allow movable, non-copyable element types?

The Qt container classes QList<T>, QVector<T> etc. require their element types to be copyable. Since C++11 ... support move-only element types? 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++11 - std::tuple_element need deep template instantination

in here http://en.cppreference.com/w/cpp/utility/tuple/tuple_element given possible implementation of std:: ... T[3] third_element;} 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++11 - C++: Overloading the [ ] operator for read and write access

In general, how do you declare the index [ ] operator of a class for both read and write accesss? I tried ... 'T& Class::operator[](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++11 - The correct way to define default argument for a friend function in C++

I want to specify a default value for a friend function, as follows: friend Matrix rot90 (const Matrix& a, int k ... way of fixing it? 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++11 - x86 mfence and C++ memory barrier

I'm checking how the compiler emits instructions for multi-core memory barriers on x86_64. The below code is ... FLAT:.LC1 call __assert_fail 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++11 - Looser Throw Specifier in C++

What does this error mean? How can I fix it? This is the header code that's causing it: ... 'virtual BadJumbleException::~BadJumbleException() 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++11 - C++ 11: Calling a C++ function periodically

I have put together a simple c++ timer class that is supposed to call a given function periodically ... ' what(): bad_function_call 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++11 - Is it defined to provide an empty range to C++ standard algorithms?

Following on from my previous question, can we prove that the standard allows us to pass an empty range to a ... in the standard wording here.) 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++11 - std::make_pair with c++ 11

Hello I have the following code: bool PinManager::insertPin(const std::string& p_pinNumber, const std::string& p_mode) { ... -14+rpi1) 4.6.3 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++11 - What is the type of a lambda function?

In C++0x, I'm wondering what the type is of a lambda function. Specifically: #include<iostream> type1 ... m compiling with visual studio 2010 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++11 - std::string::assign vs std::string::operator=

I coded in Borland C++ ages ago, and now I'm trying to understand the "new"(to me) C+11 (I know, ... memory, unless there's a big difference) 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++11 - C++ standard: do namespace-scoped constexpr variables have internal linkage?

Imagine we have a header foo.h containing the following: #ifndef FOO_H_ #define FOO_H_ namespace foo { constexpr std: ... says in this answer.) 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++11 - C++ function types

I have a problem understanding function types (they appear e.g. as the Signature template parameter of a ... outside of template parameters? 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++11 - C++ reference changes when push_back new element to std::vector

I am not sure what to make of this - please tell me what's wrong with the code below. I modified my ... VS 2012 Thanks guys. Much 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++11 - Can you make a computed goto in C++

Fortran has a computationally efficient called a 'computed goto'. The construct uses an index into a branch ... and proper. Thanx everyone. See Question&Answers more detail:os...

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

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