请考虑以下代码:
#include <iostream>
#include <memory>
#include <vector>
using namespace std;
struct A
{
int a;
A(int a_):a(a_) {}
};
int main()
{
vector<auto_ptr<A> > as;
for (int i = 0; i < 10; i++)
{
auto_ptr<A> a(new A(i));
as.push_back(a);
}
for (vector<auto_ptr<A> >::iterator it = as.begin(); it != as.end(); ++it)
cout << (*it)->a << endl;
}
当试图编译它时,我从g++中得到以下模糊的编译器错误:
g++ -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"src/proba.d" -MT"src/proba.d" -o"src/proba.o" "../src/proba.cpp"
/usr/include/c++/4.1.2/ext/new_allocator.h: In member function âvoid __gnu_cxx::new_allocator<_Tp>::construct(_Tp*, const _Tp&) [with _Tp = std::auto_ptr<A>]â:
/usr/include/c++/4.1.2/bits/stl_vector.h:606: instantiated from âvoid std::vector<_Tp, _Alloc>::push_back(const _Tp&) [with _Tp = std::auto_ptr<A>, _Alloc = std::allocator<std::auto_ptr<A> >]â
../src/proba.cpp:19: instantiated from here
/usr/include/c++/4.1.2/ext/new_allocator.h:104: error: passing âconst std::auto_ptr<A>â as âthisâ argument of âstd::auto_ptr<_Tp>::operator std::auto_ptr_ref<_Tp1>() [with _Tp1 = A, _Tp = A]â discards qualifiers
/usr/include/c++/4.1.2/bits/vector.tcc: In member function âvoid std::vector<_Tp, _Alloc>::_M_insert_aux(__gnu_cxx::__normal_iterator<typename std::_Vector_base<_Tp, _Alloc>::_Tp_alloc_type::pointer, std::vector<_Tp, _Alloc> >, const _Tp&) [with _Tp = std::auto_ptr<A>, _Alloc = std::allocator<std::auto_ptr<A> >]â:
/usr/include/c++/4.1.2/bits/stl_vector.h:610: instantiated from âvoid std::vector<_Tp, _Alloc>::push_back(const _Tp&) [with _Tp = std::auto_ptr<A>, _Alloc = std::allocator<std::auto_ptr<A> >]â
../src/proba.cpp:19: instantiated from here
/usr/include/c++/4.1.2/bits/vector.tcc:256: error: passing âconst std::auto_ptr<A>â as âthisâ argument of âstd::auto_ptr<_Tp>::operator std::auto_ptr_ref<_Tp1>() [with _Tp1 = A, _Tp = A]â discards qualifiers
/usr/include/c++/4.1.2/bits/stl_construct.h: In function âvoid std::_Construct(_T1*, const _T2&) [with _T1 = std::auto_ptr<A>, _T2 = std::auto_ptr<A>]â:
/usr/include/c++/4.1.2/bits/stl_uninitialized.h:86: instantiated from â_ForwardIterator std::__uninitialized_copy_aux(_InputIterator, _InputIterator, _ForwardIterator, __false_type) [with _InputIterator = __gnu_cxx::__normal_iterator<std::auto_ptr<A>*, std::vector<std::auto_ptr<A>, std::allocator<std::auto_ptr<A> > > >, _ForwardIterator = __gnu_cxx::__normal_iterator<std::auto_ptr<A>*, std::vector<std::auto_ptr<A>, std::allocator<std::auto_ptr<A> > > >]â
/usr/include/c++/4.1.2/bits/stl_uninitialized.h:113: instantiated from â_ForwardIterator std::uninitialized_copy(_InputIterator, _InputIterator, _ForwardIterator) [with _InputIterator = __gnu_cxx::__normal_iterator<std::auto_ptr<A>*, std::vector<std::auto_ptr<A>, std::allocator<std::auto_ptr<A> > > >, _ForwardIterator = __gnu_cxx::__normal_iterator<std::auto_ptr<A>*, std::vector<std::auto_ptr<A>, std::allocator<std::auto_ptr<A> > > >]â
/usr/include/c++/4.1.2/bits/stl_uninitialized.h:254: instantiated from â_ForwardIterator std::__uninitialized_copy_a(_InputIterator, _InputIterator, _ForwardIterator, std::allocator<_Tp>) [with _InputIterator = __gnu_cxx::__normal_iterator<std::auto_ptr<A>*, std::vector<std::auto_ptr<A>, std::allocator<std::auto_ptr<A> > > >, _ForwardIterator = __gnu_cxx::__normal_iterator<std::auto_ptr<A>*, std::vector<std::auto_ptr<A>, std::allocator<std::auto_ptr<A> > > >, _Tp = std::auto_ptr<A>]â
/usr/include/c++/4.1.2/bits/vector.tcc:279: instantiated from âvoid std::vector<_Tp, _Alloc>::_M_insert_aux(__gnu_cxx::__normal_iterator<typename std::_Vector_base<_Tp, _Alloc>::_Tp_alloc_type::pointer, std::vector<_Tp, _Alloc> >, const _Tp&) [with _Tp = std::auto_ptr<A>, _Alloc = std::allocator<std::auto_ptr<A> >]â
/usr/include/c++/4.1.2/bits/stl_vector.h:610: instantiated from âvoid std::vector<_Tp, _Alloc>::push_back(const _Tp&) [with _Tp = std::auto_ptr<A>, _Alloc = std::allocator<std::auto_ptr<A> >]â
../src/proba.cpp:19: instantiated from here
/usr/include/c++/4.1.2/bits/stl_construct.h:81: error: passing âconst std::auto_ptr<A>â as âthisâ argument of âstd::auto_ptr<_Tp>::operator std::auto_ptr_ref<_Tp1>() [with _Tp1 = A, _Tp = A]â discards qualifiers
make: *** [src/proba.o] Error 1
我觉得这里的警察有些问题。这是不是意味着
auto_ptr
不能用于
vector
S?