Error with xstdde "could not deduce template argument..." - c++

Question

I'm working on a asteroids game replica. This error I'm getting is beyond my understanding so I hope you can help.
In my code I have a class name asteroid that stores every asteroid object. Within this class I have a public function that's called create() which has the parameter sf::ConvexShape (if you don't know what sf::ConvexShape is, it is a function in the SFML library). I also have a std::map<asteroid, sf::ConvexShape> to store asteroid objects as the key and their shapes as the .second
The error is a runtime error, everything is fine in the compiler. The error reports are gibberish to me, but there was a part that mentioned "iterator" and "std::vector" which makes me think I'm doing something wrong passing iterators to the create() function?
Here is the error log:
Error 5 error C2784: 'bool std::operator <(const std::vector<_Ty,_Alloc> &,const std::vector<_Ty,_Alloc> &)' : could not deduce template argument for 'const std::vector<_Ty,_Alloc> &' from 'const asteroid' C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\include\xstddef 180 1 SFML testing
Error 10 error C2784: 'bool std::operator <(const std::reverse_iterator<_RanIt> &,const std::reverse_iterator<_RanIt2> &)' : could not deduce template argument for 'const std::reverse_iterator<_RanIt> &' from 'const asteroid' C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\include\xstddef 180 1 SFML testing
Error 12 error C2784: 'bool std::operator <(const std::pair<_Ty1,_Ty2> &,const std::pair<_Ty1,_Ty2> &)' : could not deduce template argument for 'const std::pair<_Ty1,_Ty2> &' from 'const asteroid' C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\include\xstddef 180 1 SFML testing
Error 9 error C2784: 'bool std::operator <(const std::move_iterator<_RanIt> &,const std::move_iterator<_RanIt2> &)' : could not deduce template argument for 'const std::move_iterator<_RanIt> &' from 'const asteroid' C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\include\xstddef 180 1 SFML testing
Error 8 error C2784: 'bool std::operator <(const std::basic_string<_Elem,_Traits,_Alloc> &,const std::basic_string<_Elem,_Traits,_Alloc> &)' : could not deduce template argument for 'const std::basic_string<_Elem,_Traits,_Alloc> &' from 'const asteroid' C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\include\xstddef 180 1 SFML testing
Error 6 error C2784: 'bool std::operator <(const std::basic_string<_Elem,_Traits,_Alloc> &,const _Elem *)' : could not deduce template argument for 'const std::basic_string<_Elem,_Traits,_Alloc> &' from 'const asteroid' C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\include\xstddef 180 1 SFML testing
Error 4 error C2784: 'bool std::operator <(const std::_Tree<_Traits> &,const std::_Tree<_Traits> &)' : could not deduce template argument for 'const std::_Tree<_Traits> &' from 'const asteroid' C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\include\xstddef 180 1 SFML testing
Error 11 error C2784: 'bool std::operator <(const std::_Revranit<_RanIt,_Base> &,const std::_Revranit<_RanIt2,_Base2> &)' : could not deduce template argument for 'const std::_Revranit<_RanIt,_Base> &' from 'const asteroid' C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\include\xstddef 180 1 SFML testing
Error 7 error C2784: 'bool std::operator <(const _Elem *,const std::basic_string<_Elem,_Traits,_Alloc> &)' : could not deduce template argument for 'const _Elem *' from 'const asteroid' C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\include\xstddef 180 1 SFML testing
Error 13 error C2676: binary '<' : 'const asteroid' does not define this operator or a conversion to a type acceptable to the predefined operator C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\include\xstddef 180 1 SFML testing
Also full sauce here.
Why am I getting these errors? How can I fix it?
Let me know if there is something I forgot to mention, its hard to know what to ask when I don't understand the problem.

Answer 1

std::map stores things in a sorted order. If you don't tell it how to sort, it will use operator <. Your problem is that given:
asteroid a, b;
a < b; // Not defined.
You need something like:
bool operator <( const asteroid& lhs, const asteroid& rhs)
{
????
}
Except that you can't use the position (because that keeps changing). Perhaps you should do:
class asteroid
{
static unsigned global_id;
unsigned id;
.... // Previous contents as before.
}
asteroid::asteroid() : id (global_id++) { ... }
and then
bool operator <( const asteroid& lhs, const asteroid& rhs)
{
lhs.id < rhs.id;
}