Why does typeid.name() return weird characters using GCC and how to make it print unmangled names?

Question

How come when I run this main.cpp:

#include <iostream> #include <typeinfo>  using namespace std;  struct Blah {};  int main() {   cout << typeid(Blah).name() << endl;   return 0; } 

By compiling it with GCC version 4.4.4:

g++ main.cpp 

I get this:

4Blah 

On Visual C++ 2008, I would get:

struct Blah 

Is there a way to make it just print Blah or struct Blah?

Answer 1

The return of name is implementation defined : an implementation is not even required to return different strings for different types.

What you get from g++ is a decorated name, that you can "demangle" using the c++filt command or __cxa_demangle.

Answer 2

The string returned is implementation defined.

What gcc is doing is returning the mangled name.
You can convert the mangled name into plain text with c++filt

> a.out | c++filt