New in the C23 standard, thetypeofoperator is a unary operator that returns the type of an expression. It can be used in type declarations, type casts, type checks, and so on. It gets the type of a variable, function, or any C expression. ...
类型转换操作符(type conversion operator)是一种特殊的类成员函数,它定义将类类型值转变为其他类型值的转换。转换操作符在类定义体内声明,在保留字 operator 之后跟着转换的目标类型。boost::ref和boost::cref就使用到了类型转换操作符。 函数原型 T1::operatorT2()const;//T1的成员函数,"(T2)a"类型转换 1. 转...
typeid, sizeof, or alignof operator applied to type T; arithmetic operator applied to a pointer to T; definition of a class with base class T; assignment to an lvalue of type T; a handler of type T, T&, or T*. (In general, when the size and layout of T must be known.)...
另外C++11的方案也是一种计算不定参数模板参数个数的方法。 1#include <iostream>2#include <string>34//in C++ 175#if((defined(_MSVC_LANG) && _MSVC_LANG >= 201703L) || __cplusplus >= 201703L)67namespace8{9template <typename T, typename... ParamTypes>10voidprintTypesImpl()11{12std::cou...
this object through b1. You may cast away the constness of b1 and modify the value to which it refers. 4.reinterpret_cast 此运算符的行为由编译器定义。可能重新解释bits意义,但也不一定如此。使用此一转型动作通常带来不可移植性。 The reinterpret_cast operator changes one data type into another. ...
template<typenameFunc>My_function&operator= (Func a_fun) {typedef typenameget_function_tag<Func>::FunType fun_tag;assign(a_fun,fun_tag());return*this; } 有了这个函数,针对函数指针和函数对象,My_function 的数据成员都可以正确的初始化了。
POD types have no virtual functions, base classes, user-defined constructors, copy constructors, assignment operator, or destructor. A You might think a POD type is a data type that arrives from outer space wrapped in a green protective covering, but POD stands for Pl...
and finally send to the output stream with padding if necessary. Doing this for all types would be quite inelegant because it implies extra allocations to make the temporary stream. A workaround is to add logic tooperator<<()for composite user defined types so they are aware of the stream...
operator==operator!= (removed in C++20) checks whether the objects refer to the same type (public member function) before checks whether the referred type precedes referred type of anothertype_info object in the implementation defined order, i.e. orders the referred types ...
New in the C23 standard, the typeof operator is a unary operator that returns the type of an expression. It can be used in type declarations, type casts, type checks, and so on. It gets the type of a variable, function, or any C expression....