static_cast fail to cast the address of vector

Question

vector<vector<int>> v;
vector<int> v0;
for(int i = 0; i < 5; i++){
    v.push_back(v0);
}
for(int i = 0; i < v.size(); i++){
    cout << static_cast<void const *>(&(v[i])) << endl;
}

I try to treat vector as an object and cout its address like above but failed, then how can I cout the vector's address.

The linker error message does not seem to have any relationship with the title of your question. — R Sahu, Mar 03 '16 at 18:50
@j_random_hacker Well, there is [an overload](http://en.cppreference.com/w/cpp/io/basic_ostream/operator_ltlt) see (7), and it should match the static cast. — πάντα ῥεῖ, Mar 03 '16 at 18:53
@πάνταῥεῖ: Quite right! Thanks for pointing that out, I'll remove my comment. — j_random_hacker, Mar 03 '16 at 18:59
You are right, the error message is misleading, I modified my question. — cxs1031, Mar 03 '16 at 19:54

score 2 · Answer 1 · edited May 23 '17 at 12:07

2

Instead of using gcc, you might want to try to compile your code with

g++ -std=c++14

Then it should work: https://ideone.com/y0DwdA.

The linker error, which I could reproduce by using gcc, is most probably related to the differences between the compilers described here.

As pointed out by @πάνταῥεῖ, the compiler flag -std=c++11 will work as well.

edited May 23 '17 at 12:07

Community

1
1

answered Mar 03 '16 at 18:57

RHertel

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I can't see any relevance for `-std=c++14 ` here? – πάντα ῥεῖ Mar 03 '16 at 19:03
@πάνταῥεῖ If you insert a space betwen `>>` in the first line, at the end of the nested vector declaration, there is none. – RHertel Mar 03 '16 at 19:05
1

`-std==c++11` or no specific flag will solve this already, unless an older `cx03` compiler is used. – πάντα ῥεῖ Mar 03 '16 at 19:07
1

@πάνταῥεῖ I agree that -std=c++11 is sufficient, but no complier flag won't work, at least not generally. I'm using g++ version 5.2.1 and the >> is a syntax error without the mentioned flags. – RHertel Mar 03 '16 at 19:08

score 1 · Answer 2 · answered Mar 03 '16 at 19:30

Compile with g++ -std=c++11 -Wall main.cc the code:

#include <iostream>
#include <vector>

int
main()
{
    using namespace std;

    vector<vector<int>> v;
    vector<int> v0;
    for(int i = 0; i < 5; i++){
        v.push_back(v0);
    }
    for(size_t i = 0; i < v.size(); i++){
        cout << reinterpret_cast<size_t>(&(v[i])) << endl;
    }
}

static_cast fail to cast the address of vector

2 Answers2