c – 程序以g编译,但在gcc中以链接器错误退出

这个代码编译精细g,但在使用gcc编译时会抛出链接器错误.这些错误的原因是什么？

$g++ traits2.cpp
$gcc traits2.cpp
/tmp/ccI7CNCY.o: In function `__static_initialization_and_destruction_0(int,int)':
traits2.cpp:(.text+0x36): undefined reference to `std::ios_base::Init::Init()'
traits2.cpp:(.text+0x3b): undefined reference to `std::ios_base::Init::~Init()'
/tmp/ccI7CNCY.o:(.eh_frame+0x11): undefined reference to `__gxx_personality_v0'
collect2: ld returned 1 exit status

traits2.ccp文件包含前面提到的带有emtpy main()函数的solution：

#include <iostream>

using namespace std;

// A default Traits class has no information
template<class T> struct Traits
{
};

// A convenient way to get the Traits of the type of a given value without
// having to explicitly write out the type
template<typename T> Traits<T> GetTraits(const T&)
{
    return Traits<T>();
}

template <int major,int minor> struct A 
{ 
    void f() 
    { 
        cout << major << endl; 
    }   
};

// Specialisation of the traits for any A<int,int>
template<int N1,int N2> struct Traits<A<N1,N2> >
{
    enum { major = N1,minor = N2 };
};

template <> struct A<4,0> 
{       
    void f() 
    { 
        cout << "Specialized:" << GetTraits(*this).major << endl; 
    }   
};

int main(int argc,char * argv[] )
{
    /*
    A<4,0> p;
    A<1,2> p2;
    p.f();
    p2.f();
    */
    return 1;
}