Stl map of China [code] 14.00 KEY{            ..... Bool operator ====== (const KEY& i) ( Bool ret;                     . .. Return ret;            } Bool operator "; (CONST KEY& i) ( Bool ret;                     . .. Return ret;            } Bool operator "(CONST KEY& i) ( Bool ret;                     . .. Return ret;            }             ....       } 14.00 VALUE{            ....      } Map<KEY, VALUE>; my_map; KEY one_key; //assign Value to one_key //insert Something here Map<KEY, VALUE>; : : iterator mit = my_map.find (one_key); [/code] Compiler incorrect report But map<KEY removed, VALUE>; : : iterator mit = my_map.find (one_key); After not being given a. Help us to see what we Stl map of China Bool operator< (const KEY& i) const Insert CONST. [code]template "Typename _Key, typename _Tp, typename _Compare = less<_Key>;. Typename _Alloc = allocator<pair<const _Key, _Tp>; "; "; 14.00 map[/code] because you compare that with the acquiescence less<KEY>;. And the definition is : less<KEY>; [code]template "Class _Tp>; Struct less : public binary_function<_Tp, _Tp, bool>;      { Bool Operator () (const _Tp& __x, const _Tp& __y) const (Return __x "__y;) It requires two parameters are the };[/code] CONST. So you write this operator< which is const, so here __x "You can not be deployed on the __y operator<. Add CONST you this is CONST this. Stl map of China Thank you, upstairs, has been resolved [ Closed window ]