STL中使用容器中的容器

#include
#include
#include
struct TEST {
    int x;
    int y;
};
int main()
{
    std::vector str;
    std::vector< std::vector > s;

    str.push_back( "a" );
    str.push_back( "b" );
    s.push_back( str );

    str.clear();

    str.push_back( "c" );
    str.push_back( "d" );
    s.push_back( str );

    std::vector >::iterator i;

    for ( i = s.begin(); i != s.end(); i++ )
    {
        std::vector::iterator ii;
        for ( ii = i->begin(); ii != i->end(); ii++ )
        {
            std::cout << *ii << "\t";
        }
        std::cout << std::endl;
    }
    return 0;
}


$ g++ test.cpp
$ ./a.out
a       b
c       d