What does this error mean?

[Mike Harrold]

Hi,

Can someone give me a good explanation of what this error actually means?
I am seeing it in gcc-3.1 (it was not there in gcc-3.0.2).

/home/src/lang/src/ThinAMString.cc: In instantiation of `std::basic_istream<_CharT, _Traits>& std::getline(std::basic_istream<_CharT, _Traits>&, std::basic_string<_CharT, _Traits, _Alloc>&) [with _CharT = char, _Traits = std::char_traits<char>, _Alloc = std::allocator<char>]':
/home/src/lang/src/ThinAMString.cc:1473:   instantiated from here
/home/src/lang/src/ThinAMString.cc:1473: explicit 
   instantiation of `std::basic_istream<_CharT, _Traits>& 
   std::getline(std::basic_istream<_CharT, _Traits>&, std::basic_string<_CharT, 
   _Traits, _Alloc>&) [with _CharT = char, _Traits = std::char_traits<char>, 
   _Alloc = std::allocator<char>]' but no definition available

TIA,

/Mike