Vector series--vector<unique_ptr<>> assignment to vector<unique_ptr<>> in combat C + +

Previous blogs about vectors you can use the Insert method to copy a vector to the back of another vector.

Previous blogs have also talked about the need to transfer ownership if the vector container is placed inside the unique_ptr.

Come on, now. 818 Howvector<unique_ptr<>> insert to vector<unique_ptr<>>

If you have a regular vector, we can use insert like this:

//inserting into a vector#include <iostream>#include <vector>intMain () {STD:: vector<int>Myvector (3, -);//100  STD:: vector<int>:: Iterator it;  it = Myvector.begin (); it = Myvector.insert (it, $);//200Myvector.insert (IT,2, -);//300  //"It" no longer valid, get a new one:it = Myvector.begin ();STD:: vector<int>Anothervector (2, -); Myvector.insert (it+2, Anothervector.begin (), Anothervector.end ());//now, A.  intMyArray [] = {501,502,503}; Myvector.insert (Myvector.begin (), myarray, myarray+3);STD::cout<<"Myvector contains:"; for(It=myvector.begin (); It<myvector.end (); it++)STD::cout<<"'<< *it;STD::cout<<' \ n ';return 0;}//output:501 502 503  -  -  -  -  $  -  -  -

But for a unique point within a vector, you can't simply use a normal iterator: you need to use the Std::make_move_iterator action on the iterator:

Look at the most reliable English description:
A move_iterator is an iterator adaptor that adapts an iterator (it) so the dereferencing it produces rvalue references (a s if Std::move is applied), while all other operations behave the same.

Just like the std::move we used before.
See examples of Use:

#include <iostream> //std::cout #include <iterator> //Std::make_move_iterator #include <vector> //std::vector #include <string> //std::string #include <algorithm> //std::copy intMain () {STD:: Vector<std::string>Foo (3);STD:: Vector<std::string>Bar {"One","both","three"};STD:: Copy (Make_move_iterator (Bar.begin ()), Make_move_iterator (Bar.end ()), Foo.begin ());//Bar now contains unspecified values; clear it:Bar.clear ();STD::cout<<"foo:"; for(STD::string& X:foo)STD::cout<<"'<< x;STD::cout<<' \ n ';return 0;}//output:Foo:one Three

The next step is our use, which is simple:

#include <iostream>#include <vector>#include <memory>using namespace STD;voidDisplay_vector ( vector<unique_ptr<int>> &vec);intMain () { vector<unique_ptr<int>> VEC; unique_ptr<int> S1 (New int(1)); unique_ptr<int> s2 (New int(2)); unique_ptr<int> S3 (New int(3)); unique_ptr<int> S4 (New int(4)); Vec.push_back (STD:: Move (S1)); Vec.push_back (STD:: Move (S2)); Vec.push_back (STD:: Move (S3)); Vec.push_back (STD:: Move (S4)); unique_ptr<int> S5 (New int(5)); vector<unique_ptr<int>> Des_vec; Des_vec.push_back (STD:: Move (S5)); Des_vec.insert (Des_vec.end (),STD:: Make_move_iterator (Vec.begin ()),STD:: Make_move_iterator (Vec.end ())); Display_vector (Des_vec);cout<<"Now, Des_vec size:"<< des_vec.size () << Endl;cout<<"Now, VEC size:"<< vec.size () << Endl;return 0;}voidDisplay_vector ( vector<unique_ptr<int>> &vec) { for(Autoit = Vec.begin (); It! = Vec.end (); it++) {cout<< **it << Endl; }//Output Result:51234Now, Des_vec size:5Now, VEC size:4

Vector series--vector<unique_ptr<>> assignment to vector<unique_ptr<>> in combat C + +