在C ++中新的返回（void *）？ [英] Does new return (void *) in C++?

问题描述

这是一个简单的问题：

使用new运算符返回类型为（void *）的指针吗？
参考新的/ delete和malloc / free？答案 - 它说： new返回一个完全类型的指针malloc void *

Does using new operator return a pointer of type (void *)? Referring to What is the difference between new/delete and malloc/free? answer - it says new returns a fully typed pointer while malloc void *

但根据 http://www.cplusplus.com/reference/new/操作符％20new /

throwing (1)    
void* operator new (std::size_t size) throw (std::bad_alloc);
nothrow (2) 
void* operator new (std::size_t size, const std::nothrow_t& nothrow_value) throw();
placement (3)   
void* operator new (std::size_t size, void* ptr) throw();

这意味着如果返回（void *）从未见过类似MyClass的代码* ptr =（MyClass *）new MyClass;

which means it returns a pointer of type (void *), if it returns (void *) I have never seen a code like MyClass *ptr = (MyClass *)new MyClass;

我很困惑。

EDIT

根据 http://www.cplusplus.com/reference/new/operator%20new/ example

As per http://www.cplusplus.com/reference/new/operator%20new/ example

std::cout << "1: ";
  MyClass * p1 = new MyClass;
      // allocates memory by calling: operator new (sizeof(MyClass))
      // and then constructs an object at the newly allocated space

  std::cout << "2: ";
  MyClass * p2 = new (std::nothrow) MyClass;
      // allocates memory by calling: operator new (sizeof(MyClass),std::nothrow)
      // and then constructs an object at the newly allocated space

因此 MyClass * p1 = new MyClass 调用 （myClass）），因为 throwing（1）

void * operator new（std :: size_t size）throw（std :: bad_alloc）; 如果我理解正确的语法，它应该返回（void *）。

So MyClass * p1 = new MyClass calls operator new (sizeof(MyClass)) and since throwing (1)
void* operator new (std::size_t size) throw (std::bad_alloc); it should return (void *) if I understand the syntax correctly.

/ p>

Thanks

推荐答案

您会混淆 operator new c> void * ）和 new 运算符（返回完全类型的指针）。

You are confusing operator new (which does return void*) and the new operator (which returns a fully-typed pointer).

void* vptr = operator new(10); // allocates 10 bytes
int* iptr = new int(10); // allocate 1 int, and initializes it to 10

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