问题
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
回答1:
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
来源:https://stackoverflow.com/questions/16396304/strange-output-of-stdtypeidname