首先，C++ 的RTTI（包括了 dynamic_cast）肯定不是个很好的设计：dynamic_cast 是有可能抛出std::bad_...
chara ='a';intb = static_cast<char>(a);//正确,将char型数据转换成int型数据double*c =newdouble;void*d = static_cast<void*>(c);//正确,将double指针转换成void指针inte =10;constintf = static_cast<constint>(e);//正确,将int型数据转换成const int型数据constintg =20;int*h = static_ca...
static_cast operator const_cast operator reinterpret_cast operator Run-Time Type Information (RTTI) Statements Namespaces Enumerations Unions Functions Operator overloading Classes and structs Lambda expressions in C++ Arrays References Pointers Exception handling in C++ ...
此函数通过尝试使用dynamic_cast运算符将arg转换为类型为B的指针,然后转换为类型为C的指针来执行此操作。 如果dynamic_cast运算符成功,那么它将返回一个指向由arg表示的对象的指针。 如果dynamic_cast失败,那么将返回0。 只能对多态类使用dynamic_cast运算符执行向下转换。 在以上示例中,所有类都是多态类,因为类A具有...
operatordouble()const{return m_real;}//类型转换函数 private: double m_real; double m_imag; }; intmain(){ //下面是正确的用法 int m=100; Complexc(12.5,23.8); long n=static_cast<long>(m);//宽转换,没有信息丢失 char ch=static_cast<char>(m);//窄转换,可能会丢失信息 ...
实现为__dynamic_cast,这里会在简单的检测失败时调用whole_type->__do_dyncast,由于我们测试的是单继承,因此会调用到__si_class_type_info::__do_dyncast这个虚函数,如果继承链很长,会一步步调用下去;在__do_dyncast中,会使用到std::typeinfo::operator==,而这个函数就有一个分支使用了__builtin_strcmp...
// dynamic_cast_8.cpp// compile with: /GR /EHsc#include<stdio.h>#include<iostream>structA{virtualvoidtest(){ printf_s("in A\n"); } };structB:A {virtualvoidtest(){ printf_s("in B\n"); }voidtest2(){ printf_s("test2 in B\n"); } };structC:B {virtualvoidtest(){ printf...
Sign in C++ C++ in Visual Studio overview Language reference Libraries C++ build process Windows programming with C++ Learn C++, C, and Assembler C++ Save Add to CollectionsAdd to plan Share via Facebookx.comLinkedInEmail Print dynamic_cast Operator ...
The dynamic_cast operator can also be used to perform a "cross cast." Using the same class hierarchy, it is possible to cast a pointer, for example, from the B subobject to the D subobject, as long as the complete object is of type E. ...
("in C\n"); }voidtest2(){ printf_s("test2 in C\n"); } };voidGlobaltest(A& a){try{ C &c =dynamic_cast<C&>(a); printf_s("in GlobalTest\n"); }catch(std::bad_cast) { printf_s("Can't cast to C\n"); } }intmain(){ A *pa =newC; A *pa2 =newB; pa->test(...