Does pop_back () really cancel out * all * iterators on std :: vector?

Question

std::vector<int> ints;

// ... fill ints with random values

for(std::vector<int>::iterator it = ints.begin(); it != ints.end(); )
{
    if(*it < 10)
    {
        *it = ints.back();
        ints.pop_back();
        continue;
    }
    it++;
}

This code does not work because it is pop_back() itnot valid when called . But I do not find any speaker talking about the validity of iterators in std::vector::pop_back().

Do you have any links to this?

Answer 1

The call pop_back()removes the last element in the vector, and therefore the iterator for this element is invalid. The call pop_back()does not invalidate the iterators for the elements until the last element, only the redistribution will do this. From Josuttis "C ++ Standard Reference Library":

, , . , , .

Answer 2

, :

23.2.4.2 ( 23.1) , (23.1.1).

23.1.1.12. 68 expressiona.pop_back() return typevoid a.erase(- a.end()) , , deque

, a.pop_back a.erase(- a.end()). :

23.2.4.3.3 - ( ) - -

, pop_back, ( ) .

, , , .

Answer 3

( , ++ 0x,

94 . 732 , pop_back ( ) :

{ iterator tmp = a.end(); 
--tmp; 
a.erase(tmp); } 

23.1.1, 12 , :

( ), - .

end() - , ():

23.2.6.4 ( vector.erase() 4):

: .

, : pop_back() .

Answer 4

SGI STL (http://www.sgi.com/tech/stl/Vector.html):

[5] . , , , . , , , reserve() , , .

, , pop_back , end(). , , , , . , - , ++ , @mikhaild. : ++ , pop_back.

- , , 10. end(). - , .

Answer 5

. Google - : . 5.

.

Answer 6

pop_back() , . ++:

, , . , , .

, , , .

it, , 10. Visual Studio debug STL , , end(), .

( , , STL-), . , , , .

Answer 7

, "it" , 10, . "it" ints.end(), "it ++" ints.end() + 1, "" ints.end(), :).

Answer 8

" " - ++. ++ 03, ++ 0x - : http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2723.pdf

" " , pop_back() {iterator = end(); --; (); }. [vector.modifiers] : ": ".

, pop_back ( ), - ( ), , , , .

Answer 9

pop_back() it, . , int 10, :

* it = ints.back();// * , .  ints.pop_back();//
 ;//

Answer 10

, , . , . , , .

for(std::vector<int>::iterator it = ints.begin(); it != ints.end(); )
{
    if(*it < 10)
        it = ints.erase( it );
    else
        ++it;
}

std::remove_if .

struct LessThanTen { bool operator()( int n ) { return n < 10; } };

ints.erase( std::remove_if( ints.begin(), ints.end(), LessThanTen() ), ints.end() );

std::remove_if ( ) , , .

Answer 11

(cplusplus.com):

, .