Syntax for universal references

This is an rvalue reference: void foo(int&& a); It does not bind to lvalues: int i = 42; foo(i); // error This is a universal reference: template<typename T> void bar(T&& b); It binds to rvalues and it also binds to lvalues: bar(i); // okay This is an rvalue reference: template<typename T> struct X { void baz(T&& c); }; It does not bind to lva

通用参考的语法

这是一个右值参考: void foo(int&& a); 它不绑定到左值: int i = 42; foo(i); // error 这是一个普遍的参考: template<typename T> void bar(T&& b); 它绑定到右值,它也绑定到左值: bar(i); // okay 这是一个右值参考: template<typename T> struct X { void baz(T&& c); }; 它不绑定到左值: X<int> x; x.baz(i); // error 为什么通用引用使用与右值引

Intuitive understanding of functions taking references of references

Possible Duplicate: What does T&& mean in C++11? For some reason, this is eluding my intuition, and I cannot find any explanation on the internet. What does it mean for a C++ function to take a reference of a reference? For example: void myFunction(int&& val); //what does this mean?! I understand the idea of passing-by-reference, so void addTwo(int& a) { a +=

直观的理解功能,参考参考文献

可能重复: T &&在C ++ 11中意味着什么? 出于某种原因,这是逃避我的直觉,我无法在互联网上找到任何解释。 对于一个C ++函数来说,引用一个引用是什么意思? 例如: void myFunction(int&& val); //what does this mean?! 我明白通过引用传递的想法,所以 void addTwo(int& a) { a += 2; } int main() { int x = 5; addTwo(x); return 0; } 工作,对我来说很直观。 这

Using C++ shared pointer's aliasing constructor with an empty shared pointer

std::shared_ptr has an aliasing constructor that allows newly created shared_ptr to share state with an existing shared pointer while pointing to some other object. I was thinking about abusing this constructor to put pointer to some global object inside shared_ptr: int global = 0; int main() { // because we point to global object we do not need to track its lifetime // so we use emp

使用C ++共享指针的别名构造函数和一个空的共享指针

std :: shared_ptr有一个别名构造函数,允许新创建的shared_ptr在指向其他对象时与现有的共享指针共享状态。 我正在考虑滥用这个构造函数把指针放在shared_ptr里面的一些全局对象中: int global = 0; int main() { // because we point to global object we do not need to track its lifetime // so we use empty shared_ptr<void> as a provider of shared state std::shared_ptr<int> p(std::sh

What does it mean const type& method

This question already has an answer here: Meaning of “const” last in a C++ method declaration? 7 answers 这意味着该函数的定义不能修改它所属的结构/类(即它不能改变实例变量)。 struct MyStruct { int i ; void go1 () { i = 5 ; } void go2 () const { i = 5 ; // error: 'this' is const } } ;

这是什么意思const类型和方法

这个问题在这里已经有了答案: C ++方法声明中最后一个“const”的含义? 7个答案 这意味着该函数的定义不能修改它所属的结构/类(即它不能改变实例变量)。 struct MyStruct { int i ; void go1 () { i = 5 ; } void go2 () const { i = 5 ; // error: 'this' is const } } ;

Why the use of const in a method with no parameters?

This question already has an answer here: Meaning of “const” last in a C++ method declaration? 7 answers What is meant with “const” at end of function declaration? [duplicate] 6 answers Banning the modification of members is not the only reason to qualify a member function as const . Whether you want to modify members or not, you can only call a member function on an object through a con

为什么在没有参数的方法中使用const?

这个问题在这里已经有了答案: C ++方法声明中最后一个“const”的含义? 7个答案 函数声明结束时的“const”是什么意思? [复制] 6个回答 禁止修改成员不是将成员函数限定为const的唯一原因。 无论您是否想要修改成员,如果成员函数标记为const ,则只能通过const上下文对对象调用成员函数: #include <iostream> #include <string> struct List { std::string reqClubName() { return m_Club;

Const declaration of a function

This question already has an answer here: Meaning of “const” last in a C++ method declaration? 7 answers These are member function declarations, presumably, not regular functions. const int getNum(int &a, int &b) const; The leftmost const means that the int being returned from this function is constant. This is a relatively meaningless distinction—sure, the int is constant, but yo

一个函数的const声明

这个问题在这里已经有了答案: C ++方法声明中最后一个“const”的含义? 7个答案 这些是成员函数声明,大概不是常规函数。 const int getNum(int &a, int &b) const; 最左边的const表示从该函数返回的int是常量。 这是一个相对无意义的区别 - 当然,int是不变的,但是在使用它之前,你会隐式地创建它的副本。 这对类返回类型有影响,但它仍然不是特别有用。 最右边的const意味着可以在一个常量对象上调用成员

What does const after function header do?

This question already has an answer here: Meaning of “const” last in a C++ method declaration? 7 answers From the Const Correctness tutorial: If you have a const object, you don't want to call methods that can change the object, so you need a way of letting the compiler know which methods can be safely called. These methods are called "const functions", and are the only func

函数头后的const是什么?

这个问题在这里已经有了答案: C ++方法声明中最后一个“const”的含义? 7个答案 从Const正确性教程: 如果你有一个const对象,你不想调用可以改变对象的方法,所以你需要一种让编译器知道哪些方法可以安全调用的方法。 这些方法被称为“const函数”,并且是可以在const对象上调用的唯一函数。 请注意,顺便说一下,只有成员方法与const方法一样合理。 请记住,在C ++中,对象的每个方法都会收到一个隐含的指向该对象的指

what does "const" mean when overloading operator in C++

This question already has an answer here: Meaning of “const” last in a C++ method declaration? 7 answers It can be used for any member function, not only operators. It means, that this function will: not be able to modify any data members (except mutable ones) will not be able to call any non- const member functions

在C ++中重载运算符时,“const”是什么意思?

这个问题在这里已经有了答案: C ++方法声明中最后一个“const”的含义? 7个答案 它可以用于任何成员函数,而不仅仅是操作符。 这意味着,这个功能将会: 不能修改任何数据成员(除了mutable数据) 将无法调用任何非const成员函数

What does const T& value() const mean?

This question already has an answer here: Meaning of “const” last in a C++ method declaration? 7 answers const T& value() const {...} This means the function value() will return a const T& type and in between (in the function) won't modify the class itself. Say I write: class Cfoo { void foo() const { //Cfoo will not be modified here } } If I directly quote

const T&value()const是什么意思?

这个问题在这里已经有了答案: C ++方法声明中最后一个“const”的含义? 7个答案 const T& value() const {...} 这意味着函数value()将返回一个const T& type,并且在两者之间(在函数中)不会修改类本身。 说我写: class Cfoo { void foo() const { //Cfoo will not be modified here } } 如果我直接引用msdn: 用const关键字声明一个成员函数指定该函数是一个“只读”函数,它不会修改调

C++ Calling methods with same signature but different scope

This question already has an answer here: Meaning of “const” last in a C++ method declaration? 7 answers Functions can be overloaded based on their const ness alone. This is an important feature of C++. // const member function: const XMLAttribute* FindAttribute( const char* name ) const; // non-const member function XMLAttribute* FindAttribute( const char* name ); In this case, the cons

C ++调用具有相同签名但范围不同的方法

这个问题在这里已经有了答案: C ++方法声明中最后一个“const”的含义? 7个答案 函数可以根据它们的const单独重载。 这是C ++的一个重要特性。 // const member function: const XMLAttribute* FindAttribute( const char* name ) const; // non-const member function XMLAttribute* FindAttribute( const char* name ); 在这种情况下, const ,使功能不同的是const以下括号。 括号之前的const不属于方法签名,而括