C/C++ / typeid 详解

最新推荐文章于 2024-09-12 14:08:01 发布

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最新推荐文章于 2024-09-12 14:08:01 发布 · 397 阅读

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#c++ #算法 #开发语言

本文通过一个C++示例程序展示了如何打印不同类型的typeid名称，包括基本数据类型、自定义类及标准库类型。这有助于理解C++中类型识别的方式。

#include <iostream>

#define PRINT(x) std::cout << "typeid(" #x ").name() = \"" << typeid(x).name() << "\"" << std::endl;

class Base {
};
class Derived : public Base {
};

int main()
{
    Base b, *pb;
    pb = NULL;
    Derived d;

    PRINT(int)
    PRINT(unsigned)
    PRINT(long)
    PRINT(unsigned long)
    PRINT(char)
    PRINT(unsigned char)
    PRINT(float)
    PRINT(double)
    PRINT(std::string)
    PRINT(Base)
    PRINT(b)
    PRINT(pb)
    PRINT(Derived)
    PRINT(d)
    PRINT(std::type_info)
    return 0;
}

结果

typeid(int).name() = "i"
typeid(unsigned).name() = "j"
typeid(long).name() = "l"
typeid(unsigned long).name() = "m"
typeid(char).name() = "c"
typeid(unsigned char).name() = "h"
typeid(float).name() = "f"
typeid(double).name() = "d"
typeid(std::string).name() = "NSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE"
typeid(Base).name() = "4Base"
typeid(b)