std :: typeid :: name()的奇怪输出 [英] Strange output of std::typeid::name()
本文介绍了std :: typeid :: name()的奇怪输出的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我使用 typeid
来获取std :: vector :: size_type的类型名称和零大小的类A,并使用以下代码( cppreference ):
# include< iostream>
#include< vector>
#include< typeinfo>
using namespace std;
class A {};
int main()
{
vector< int> v(10);
vector< int> :: size_type s = v.size();
A a;
cout<< typeid(s).name()< endl
cout<< typeid(a).name()<< endl
};
我有这个输出:
m
1A
之前A是空基类优化的结果,但m代表什么,这是正常吗?
我使用以下gcc版本:g ++(Ubuntu 4.4.3-4ubuntu5.1)4.4.3
c ++ filt 可读:
$ ./test | c ++ filt -t
unsigned long
A
I used typeid
to get the type names of the std::vector::size_type and a zero sized class A with the following code (cppreference):
#include<iostream>
#include <vector>
#include <typeinfo>
using namespace std;
class A {};
int main()
{
vector<int> v(10);
vector<int>::size_type s = v.size();
A a;
cout << typeid(s).name() << endl;
cout << typeid(a).name() << endl;
};
And I got this as output:
m
1A
I guess that "1" before "A" is a result of the Empty Base Class Optimization, but what does "m" stand for and is this normal?
I am using the following gcc version: g++ (Ubuntu 4.4.3-4ubuntu5.1) 4.4.3
解决方案
G++ uses implementation-defined naming for the types, but it also offers the utility c++filt
to make them human-readable:
$ ./test | c++filt -t
unsigned long
A
这篇关于std :: typeid :: name()的奇怪输出的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!
查看全文