关于定义"string"型的堆栈的问题

vc6.0(sp6)
调程序时，出现6个warning，为了确定问题所在，我编译如下源代码：
#include <iostream>
#include <stack>
#include <string>
using namespace std;
void main()
{
stack<string> n;
}
出现6个“warning”，这是什么原因？问题出在哪里？
编译结果：
Compiling...
test.cpp
d:\program files\vc98\include\deque(208) : warning C4786: 'std::reverse_iterator<std::deque<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > >:
:const_iterator,std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::basic_string<char,std::char_traits<char>,std::allocator<char> > const &,std::basic_string<char,std::char_traits<char>,std::allocator<char> > const *,int>' : id
entifier was truncated to '255' characters in the debug information
d:\program files\vc98\include\deque(207) : while compiling class-template member function '__thiscall std::deque<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::allocator<std::basic_string<char,std::char_traits<char
>,std::allocator<char> > > >::~std::deque<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > >(void)'
d:\program files\vc98\include\deque(208) : warning C4786: 'std::reverse_iterator<std::deque<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > >:
:iterator,std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::basic_string<char,std::char_traits<char>,std::allocator<char> > &,std::basic_string<char,std::char_traits<char>,std::allocator<char> > *,int>' : identifier was trunc
ated to '255' characters in the debug information
d:\program files\vc98\include\deque(207) : while compiling class-template member function '__thiscall std::deque<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::allocator<std::basic_string<char,std::char_traits<char
>,std::allocator<char> > > >::~std::deque<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > >(void)'
warning C4786: 'std::stack<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::deque<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocat
or<char> > > > >::~stack<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::deque<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator
<char> > > > >' : identifier was truncated to '255' characters in the debug information
d:\program files\vc98\include\stack(22) : warning C4786: 'std::stack<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::deque<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::allocator<std::basic_strin
g<char,std::char_traits<char>,std::allocator<char> > > > >::stack<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::deque<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::allocator<std::basic_string<c
har,std::char_traits<char>,std::allocator<char> > > > >' : identifier was truncated to '255' characters in the debug information
d:\program files\vc98\include\deque(208) : warning C4786: 'std::deque<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > >::~deque<std::basic_str
ing<char,std::char_traits<char>,std::allocator<char> >,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > >' : identifier was truncated to '255' characters in the debug information
d:\program files\vc98\include\deque(191) : warning C4786: 'std::deque<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > >::deque<std::basic_stri
ng<char,std::char_traits<char>,std::allocator<char> >,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > >' : identifier was truncated to '255' characters in the debug information

test.obj - 0 error(s), 6 warning(s)