hedgezzz的部落格

struct Mars_
{
    int ix ;
    char iy[18] ;
    double iz ;
};
typedef struct Mars_ Mars ;

vector<unique_ptr<Mars> > vec ;

void NewItem(const Mars& m)
{

    void* buffer ;
    if (posix_memalign(&buffer, 64,sizeof(Mars)) != 0)
    {
        perror("posix_memalign did not work!");
        abort() ;
    }
    printf("address=(%p) \n",buffer) ;
    Mars* ptr = new(buffer) Mars() ;
    ptr->ix = m.ix ;
    strcpy(ptr->iy,m.iy) ;
    ptr->iz = m.iz ;
    vec.emplace_back(ptr) ;
}
int main()
{
    Mars m ;
    char s[10] ;
    strcpy(s,"hello") ;
    for(int idx=0;idx<10;idx++)
    {
        m.ix = idx ;
        char stmp[18] ;
        sprintf(stmp,"%s%02d",s,idx) ;
        strcpy(m.iy,stmp) ;
        m.iz = idx * idx * 1.1 ;
        NewItem(m) ;
    }
    vector<unique_ptr<Mars> >::iterator it ;
    for (it = vec.begin() ; it != vec.end(); ++it)
    {
        cout << (*it)->ix << " " ;
        cout << (*it)->iy << " " ;
        cout << (*it)->iz << endl  ;
    }
}

output :

address=(0xf4d040)
address=(0xf4d100)
address=(0xf4d1c0)
address=(0xf4d280)
address=(0xf4d300)
address=(0xf4d3c0)
address=(0xf4d440)
address=(0xf4d500)
address=(0xf4d580)
address=(0xf4d680)
0 hello00 0
1 hello01 1.1
2 hello02 4.4
3 hello03 9.9
4 hello04 17.6
5 hello05 27.5
6 hello06 39.6
7 hello07 53.9
8 hello08 70.4
9 hello09 89.1