The following example will not compile using g++ 4.8.2:
#include <iostream>
#include <vector>
using namespace std;
int main() {
vector<int> v {1, 2, 3};
v.erase(v.cbegin()); // Compiler complains
return 0;
}
The compiler says the following. (It isn't very readable, but it's complaining that there's not a known conversion between vector<int>::const_iterator
and vector<int>::iterator
.)
prog.cpp: In function ‘int main()’:
prog.cpp:8:20: error: no matching function for call to ‘std::vector<int>::erase(std::vector<int>::const_iterator)’
v.erase(v.cbegin());
^
prog.cpp:8:20: note: candidates are:
In file included from /usr/include/c++/4.8/vector:69:0,
from prog.cpp:2:
/usr/include/c++/4.8/bits/vector.tcc:134:5: note: std::vector<_Tp, _Alloc>::iterator std::vector<_Tp, _Alloc>::erase(std::vector<_Tp, _Alloc>::iterator) [with _Tp = int; _Alloc = std::allocator<int>; std::vector<_Tp, _Alloc>::iterator = __gnu_cxx::__normal_iterator<int*, std::vector<int> >; typename std::_Vector_base<_Tp, _Alloc>::pointer = int*]
vector<_Tp, _Alloc>::
^
/usr/include/c++/4.8/bits/vector.tcc:134:5: note: no known conversion for argument 1 from ‘std::vector<int>::const_iterator {aka __gnu_cxx::__normal_iterator<const int*, std::vector<int> >}’ to ‘std::vector<int>::iterator {aka __gnu_cxx::__normal_iterator<int*, std::vector<int> >}’
/usr/include/c++/4.8/bits/vector.tcc:146:5: note: std::vector<_Tp, _Alloc>::iterator std::vector<_Tp, _Alloc>::erase(std::vector<_Tp, _Alloc>::iterator, std::vector<_Tp, _Alloc>::iterator) [with _Tp = int; _Alloc = std::allocator<int>; std::vector<_Tp, _Alloc>::iterator = __gnu_cxx::__normal_iterator<int*, std::vector<int> >; typename std::_Vector_base<_Tp, _Alloc>::pointer = int*]
vector<_Tp, _Alloc>::
^
/usr/include/c++/4.8/bits/vector.tcc:146:5: note: candidate expects 2 arguments, 1 provided
Why? The C++11 standard plainly states, in §23.3.6.5, that the vector::erase
function takes a const_iterator
. (Paraphrases are here and here.)
What's a good workaround, assuming that I must use a const_iterator
?
See Question&Answers more detail:
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