【发布时间】：2017-06-11 04:10:38
【问题描述】：
我的问题在以下 .h 中：
#include <iostream>
#include <map>
#include <vector>
struct Node {
int data;
};
class Graph {
std::map< Node, std::vector<Node> > edge_map;
public:
Graph();
void add_neighbor(Node cur_node, Node new_node);
void remove_neighbor(Node cur_node, Node del_node);
virtual ~Graph();
};
并试图实现 add_neighbor 函数，但我正在摸索细节并需要一些指导。到目前为止我得到的（不是功能性的）如下：
void Graph::add_neighbor(Node cur_node, Node new_node) {
if (edge_map.find(cur_node) == edge_map.end()) {
edge_map.insert(std::pair<Node, std::vector<Node> >(cur_node, std::vector<Node>()));
edge_map[cur_node].push_back(new_node);
}
else {
edge_map[cur_node].push_back(new_node);
}
}
我可以复制 g++ -std=c++11 向我抛出的爆炸，但这不是很有帮助。如何将映射包含为类成员，其中键、值是结构、结构向量，然后在 .cpp 中有一个可以添加它的函数？我还需要删除函数，但是一旦我了解了如何处理插入函数中的数据，我想我就会知道我需要什么。
编辑（包括编译器呕吐物）：
In file included from /usr/include/c++/4.8/string:48:0,
from /usr/include/c++/4.8/bits/locale_classes.h:40,
from /usr/include/c++/4.8/bits/ios_base.h:41,
from /usr/include/c++/4.8/ios:42,
from /usr/include/c++/4.8/ostream:38,
from /usr/include/c++/4.8/iostream:39,
from graph.cpp:1:
/usr/include/c++/4.8/bits/stl_function.h: In instantiation of ‘bool std::less<_Tp>::operator()(const _Tp&, const _Tp&) const [with _Tp = Node]’:
/usr/include/c++/4.8/bits/stl_map.h:463:31: required from ‘std::map<_Key, _Tp, _Compare, _Alloc>::mapped_type& std::map<_Key, _Tp, _Compare, _Alloc>::operator[](const key_type&) [with _Key = Node; _Tp = std::vector<Node>; _Compare = std::less<Node>; _Alloc = std::allocator<std::pair<const Node, std::vector<Node> > >; std::map<_Key, _Tp, _Compare, _Alloc>::mapped_type = std::vector<Node>; std::map<_Key, _Tp, _Compare, _Alloc>::key_type = Node]’
graph.cpp:14:26: required from here
/usr/include/c++/4.8/bits/stl_function.h:235:20: error: no match for ‘operator<’ (operand types are ‘const Node’ and ‘const Node’)
{ return __x < __y; }
^
/usr/include/c++/4.8/bits/stl_function.h:235:20: note: candidates are:
In file included from /usr/include/c++/4.8/bits/stl_algobase.h:64:0,
from /usr/include/c++/4.8/bits/char_traits.h:39,
from /usr/include/c++/4.8/ios:40,
from /usr/include/c++/4.8/ostream:38,
from /usr/include/c++/4.8/iostream:39,
from graph.cpp:1:
/usr/include/c++/4.8/bits/stl_pair.h:220:5: note: template<class _T1, class _T2> constexpr bool std::operator<(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)
operator<(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
^
/usr/include/c++/4.8/bits/stl_pair.h:220:5: note: template argument deduction/substitution failed:
In file included from /usr/include/c++/4.8/string:48:0,
from /usr/include/c++/4.8/bits/locale_classes.h:40,
from /usr/include/c++/4.8/bits/ios_base.h:41,
from /usr/include/c++/4.8/ios:42,
from /usr/include/c++/4.8/ostream:38,
from /usr/include/c++/4.8/iostream:39,
from graph.cpp:1:
/usr/include/c++/4.8/bits/stl_function.h:235:20: note: ‘const Node’ is not derived from ‘const std::pair<_T1, _T2>’
{ return __x < __y; }
^
In file included from /usr/include/c++/4.8/bits/stl_algobase.h:67:0,
from /usr/include/c++/4.8/bits/char_traits.h:39,
from /usr/include/c++/4.8/ios:40,
from /usr/include/c++/4.8/ostream:38,
from /usr/include/c++/4.8/iostream:39,
from graph.cpp:1:
/usr/include/c++/4.8/bits/stl_iterator.h:297:5: note: template<class _Iterator> bool std::operator<(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)
operator<(const reverse_iterator<_Iterator>& __x,
^
/usr/include/c++/4.8/bits/stl_iterator.h:297:5: note: template argument deduction/substitution failed:
In file included from /usr/include/c++/4.8/string:48:0,
from /usr/include/c++/4.8/bits/locale_classes.h:40,
from /usr/include/c++/4.8/bits/ios_base.h:41,
from /usr/include/c++/4.8/ios:42,
from /usr/include/c++/4.8/ostream:38,
from /usr/include/c++/4.8/iostream:39,
from graph.cpp:1:
/usr/include/c++/4.8/bits/stl_function.h:235:20: note: ‘const Node’ is not derived from ‘const std::reverse_iterator<_Iterator>’
{ return __x < __y; }
^
In file included from /usr/include/c++/4.8/bits/stl_algobase.h:67:0,
from /usr/include/c++/4.8/bits/char_traits.h:39,
from /usr/include/c++/4.8/ios:40,
from /usr/include/c++/4.8/ostream:38,
from /usr/include/c++/4.8/iostream:39,
from graph.cpp:1:
/usr/include/c++/4.8/bits/stl_iterator.h:347:5: note: template<class _IteratorL, class _IteratorR> bool std::operator<(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)
operator<(const reverse_iterator<_IteratorL>& __x,
^
/usr/include/c++/4.8/bits/stl_iterator.h:347:5: note: template argument deduction/substitution failed:
In file included from /usr/include/c++/4.8/string:48:0,
from /usr/include/c++/4.8/bits/locale_classes.h:40,
from /usr/include/c++/4.8/bits/ios_base.h:41,
from /usr/include/c++/4.8/ios:42,
from /usr/include/c++/4.8/ostream:38,
from /usr/include/c++/4.8/iostream:39,
from graph.cpp:1:
/usr/include/c++/4.8/bits/stl_function.h:235:20: note: ‘const Node’ is not derived from ‘const std::reverse_iterator<_Iterator>’
{ return __x < __y; }
^
In file included from /usr/include/c++/4.8/bits/stl_algobase.h:67:0,
from /usr/include/c++/4.8/bits/char_traits.h:39,
from /usr/include/c++/4.8/ios:40,
from /usr/include/c++/4.8/ostream:38,
from /usr/include/c++/4.8/iostream:39,
from graph.cpp:1:
/usr/include/c++/4.8/bits/stl_iterator.h:1055:5: note: template<class _IteratorL, class _IteratorR> bool std::operator<(const std::move_iterator<_Iterator>&, const std::move_iterator<_IteratorR>&)
operator<(const move_iterator<_IteratorL>& __x,
^
/usr/include/c++/4.8/bits/stl_iterator.h:1055:5: note: template argument deduction/substitution failed:
In file included from /usr/include/c++/4.8/string:48:0,
from /usr/include/c++/4.8/bits/locale_classes.h:40,
from /usr/include/c++/4.8/bits/ios_base.h:41,
from /usr/include/c++/4.8/ios:42,
from /usr/include/c++/4.8/ostream:38,
from /usr/include/c++/4.8/iostream:39,
from graph.cpp:1:
/usr/include/c++/4.8/bits/stl_function.h:235:20: note: ‘const Node’ is not derived from ‘const std::move_iterator<_Iterator>’
{ return __x < __y; }
^
In file included from /usr/include/c++/4.8/bits/stl_algobase.h:67:0,
from /usr/include/c++/4.8/bits/char_traits.h:39,
from /usr/include/c++/4.8/ios:40,
from /usr/include/c++/4.8/ostream:38,
from /usr/include/c++/4.8/iostream:39,
from graph.cpp:1:
/usr/include/c++/4.8/bits/stl_iterator.h:1061:5: note: template<class _Iterator> bool std::operator<(const std::move_iterator<_Iterator>&, const std::move_iterator<_Iterator>&)
operator<(const move_iterator<_Iterator>& __x,
^
/usr/include/c++/4.8/bits/stl_iterator.h:1061:5: note: template argument deduction/substitution failed:
In file included from /usr/include/c++/4.8/string:48:0,
from /usr/include/c++/4.8/bits/locale_classes.h:40,
from /usr/include/c++/4.8/bits/ios_base.h:41,
from /usr/include/c++/4.8/ios:42,
from /usr/include/c++/4.8/ostream:38,
from /usr/include/c++/4.8/iostream:39,
from graph.cpp:1:
/usr/include/c++/4.8/bits/stl_function.h:235:20: note: ‘const Node’ is not derived from ‘const std::move_iterator<_Iterator>’
{ return __x < __y; }
^
In file included from /usr/include/c++/4.8/string:52:0,
from /usr/include/c++/4.8/bits/locale_classes.h:40,
from /usr/include/c++/4.8/bits/ios_base.h:41,
from /usr/include/c++/4.8/ios:42,
from /usr/include/c++/4.8/ostream:38,
from /usr/include/c++/4.8/iostream:39,
from graph.cpp:1:
/usr/include/c++/4.8/bits/basic_string.h:2569:5: note: template<class _CharT, class _Traits, class _Alloc> bool std::operator<(const std::basic_string<_CharT, _Traits, _Alloc>&, const std::basic_string<_CharT, _Traits, _Alloc>&)
operator<(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
^
/usr/include/c++/4.8/bits/basic_string.h:2569:5: note: template argument deduction/substitution failed:
In file included from /usr/include/c++/4.8/string:48:0,
from /usr/include/c++/4.8/bits/locale_classes.h:40,
from /usr/include/c++/4.8/bits/ios_base.h:41,
from /usr/include/c++/4.8/ios:42,
from /usr/include/c++/4.8/ostream:38,
from /usr/include/c++/4.8/iostream:39,
from graph.cpp:1:
/usr/include/c++/4.8/bits/stl_function.h:235:20: note: ‘const Node’ is not derived from ‘const std::basic_string<_CharT, _Traits, _Alloc>’
{ return __x < __y; }
^
In file included from /usr/include/c++/4.8/string:52:0,
from /usr/include/c++/4.8/bits/locale_classes.h:40,
from /usr/include/c++/4.8/bits/ios_base.h:41,
from /usr/include/c++/4.8/ios:42,
from /usr/include/c++/4.8/ostream:38,
from /usr/include/c++/4.8/iostream:39,
from graph.cpp:1:
/usr/include/c++/4.8/bits/basic_string.h:2581:5: note: template<class _CharT, class _Traits, class _Alloc> bool std::operator<(const std::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)
operator<(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
^
/usr/include/c++/4.8/bits/basic_string.h:2581:5: note: template argument deduction/substitution failed:
In file included from /usr/include/c++/4.8/string:48:0,
from /usr/include/c++/4.8/bits/locale_classes.h:40,
from /usr/include/c++/4.8/bits/ios_base.h:41,
from /usr/include/c++/4.8/ios:42,
from /usr/include/c++/4.8/ostream:38,
from /usr/include/c++/4.8/iostream:39,
from graph.cpp:1:
/usr/include/c++/4.8/bits/stl_function.h:235:20: note: ‘const Node’ is not derived from ‘const std::basic_string<_CharT, _Traits, _Alloc>’
{ return __x < __y; }
^
In file included from /usr/include/c++/4.8/string:52:0,
from /usr/include/c++/4.8/bits/locale_classes.h:40,
from /usr/include/c++/4.8/bits/ios_base.h:41,
from /usr/include/c++/4.8/ios:42,
from /usr/include/c++/4.8/ostream:38,
from /usr/include/c++/4.8/iostream:39,
from graph.cpp:1:
/usr/include/c++/4.8/bits/basic_string.h:2593:5: note: template<class _CharT, class _Traits, class _Alloc> bool std::operator<(const _CharT*, const std::basic_string<_CharT, _Traits, _Alloc>&)
operator<(const _CharT* __lhs,
^
/usr/include/c++/4.8/bits/basic_string.h:2593:5: note: template argument deduction/substitution failed:
In file included from /usr/include/c++/4.8/string:48:0,
from /usr/include/c++/4.8/bits/locale_classes.h:40,
from /usr/include/c++/4.8/bits/ios_base.h:41,
from /usr/include/c++/4.8/ios:42,
from /usr/include/c++/4.8/ostream:38,
from /usr/include/c++/4.8/iostream:39,
from graph.cpp:1:
/usr/include/c++/4.8/bits/stl_function.h:235:20: note: mismatched types ‘const _CharT*’ and ‘Node’
{ return __x < __y; }
^
In file included from /usr/include/c++/4.8/vector:64:0,
from graph.cpp:2:
/usr/include/c++/4.8/bits/stl_vector.h:1421:5: note: template<class _Tp, class _Alloc> bool std::operator<(const std::vector<_Tp, _Alloc>&, const std::vector<_Tp, _Alloc>&)
operator<(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
^
/usr/include/c++/4.8/bits/stl_vector.h:1421:5: note: template argument deduction/substitution failed:
In file included from /usr/include/c++/4.8/string:48:0,
from /usr/include/c++/4.8/bits/locale_classes.h:40,
from /usr/include/c++/4.8/bits/ios_base.h:41,
from /usr/include/c++/4.8/ios:42,
from /usr/include/c++/4.8/ostream:38,
from /usr/include/c++/4.8/iostream:39,
from graph.cpp:1:
/usr/include/c++/4.8/bits/stl_function.h:235:20: note: ‘const Node’ is not derived from ‘const std::vector<_Tp, _Alloc>’
{ return __x < __y; }
^
In file included from /usr/include/c++/4.8/tuple:39:0,
from /usr/include/c++/4.8/functional:55,
from /usr/include/c++/4.8/bits/stl_algo.h:66,
from /usr/include/c++/4.8/algorithm:62,
from graph.cpp:3:
/usr/include/c++/4.8/array:238:5: note: template<class _Tp, long unsigned int _Nm> bool std::operator<(const std::array<_Tp, _Nm>&, const std::array<_Tp, _Nm>&)
operator<(const array<_Tp, _Nm>& __a, const array<_Tp, _Nm>& __b)
^
/usr/include/c++/4.8/array:238:5: note: template argument deduction/substitution failed:
In file included from /usr/include/c++/4.8/string:48:0,
from /usr/include/c++/4.8/bits/locale_classes.h:40,
from /usr/include/c++/4.8/bits/ios_base.h:41,
from /usr/include/c++/4.8/ios:42,
from /usr/include/c++/4.8/ostream:38,
from /usr/include/c++/4.8/iostream:39,
from graph.cpp:1:
/usr/include/c++/4.8/bits/stl_function.h:235:20: note: ‘const Node’ is not derived from ‘const std::array<_Tp, _Nm>’
{ return __x < __y; }
^
In file included from /usr/include/c++/4.8/functional:55:0,
from /usr/include/c++/4.8/bits/stl_algo.h:66,
from /usr/include/c++/4.8/algorithm:62,
from graph.cpp:3:
/usr/include/c++/4.8/tuple:824:5: note: template<class ... _TElements, class ... _UElements> constexpr bool std::operator<(const std::tuple<_Elements ...>&, const std::tuple<_Elements ...>&)
operator<(const tuple<_TElements...>& __t,
^
/usr/include/c++/4.8/tuple:824:5: note: template argument deduction/substitution failed:
In file included from /usr/include/c++/4.8/string:48:0,
from /usr/include/c++/4.8/bits/locale_classes.h:40,
from /usr/include/c++/4.8/bits/ios_base.h:41,
from /usr/include/c++/4.8/ios:42,
from /usr/include/c++/4.8/ostream:38,
from /usr/include/c++/4.8/iostream:39,
from graph.cpp:1:
/usr/include/c++/4.8/bits/stl_function.h:235:20: note: ‘const Node’ is not derived from ‘const std::tuple<_Elements ...>’
{ return __x < __y; }
^
In file included from /usr/include/c++/4.8/map:60:0,
from graph.h:2,
from graph.cpp:4:
/usr/include/c++/4.8/bits/stl_tree.h:917:5: note: template<class _Key, class _Val, class _KeyOfValue, class _Compare, class _Alloc> bool std::operator<(const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&, const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>&)
operator<(const _Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>& __x,
^
/usr/include/c++/4.8/bits/stl_tree.h:917:5: note: template argument deduction/substitution failed:
In file included from /usr/include/c++/4.8/string:48:0,
from /usr/include/c++/4.8/bits/locale_classes.h:40,
from /usr/include/c++/4.8/bits/ios_base.h:41,
from /usr/include/c++/4.8/ios:42,
from /usr/include/c++/4.8/ostream:38,
from /usr/include/c++/4.8/iostream:39,
from graph.cpp:1:
/usr/include/c++/4.8/bits/stl_function.h:235:20: note: ‘const Node’ is not derived from ‘const std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>’
{ return __x < __y; }
^
In file included from /usr/include/c++/4.8/map:61:0,
from graph.h:2,
from graph.cpp:4:
/usr/include/c++/4.8/bits/stl_map.h:979:5: note: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator<(const std::map<_Key, _Tp, _Compare, _Alloc>&, const std::map<_Key, _Tp, _Compare, _Alloc>&)
operator<(const map<_Key, _Tp, _Compare, _Alloc>& __x,
^
/usr/include/c++/4.8/bits/stl_map.h:979:5: note: template argument deduction/substitution failed:
In file included from /usr/include/c++/4.8/string:48:0,
from /usr/include/c++/4.8/bits/locale_classes.h:40,
from /usr/include/c++/4.8/bits/ios_base.h:41,
from /usr/include/c++/4.8/ios:42,
from /usr/include/c++/4.8/ostream:38,
from /usr/include/c++/4.8/iostream:39,
from graph.cpp:1:
/usr/include/c++/4.8/bits/stl_function.h:235:20: note: ‘const Node’ is not derived from ‘const std::map<_Key, _Tp, _Compare, _Alloc>’
{ return __x < __y; }
^
In file included from /usr/include/c++/4.8/map:62:0,
from graph.h:2,
from graph.cpp:4:
/usr/include/c++/4.8/bits/stl_multimap.h:881:5: note: template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator<(const std::multimap<_Key, _Tp, _Compare, _Alloc>&, const std::multimap<_Key, _Tp, _Compare, _Alloc>&)
operator<(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
^
/usr/include/c++/4.8/bits/stl_multimap.h:881:5: note: template argument deduction/substitution failed:
In file included from /usr/include/c++/4.8/string:48:0,
from /usr/include/c++/4.8/bits/locale_classes.h:40,
from /usr/include/c++/4.8/bits/ios_base.h:41,
from /usr/include/c++/4.8/ios:42,
from /usr/include/c++/4.8/ostream:38,
from /usr/include/c++/4.8/iostream:39,
from graph.cpp:1:
/usr/include/c++/4.8/bits/stl_function.h:235:20: note: ‘const Node’ is not derived from ‘const std::multimap<_Key, _Tp, _Compare, _Alloc>’
{ return __x < __y; }
^
【问题讨论】：
-
这种爆炸会很有帮助，因为在其中，尝试使用 <.> 比较两个
Nodes 时会出错 -
你的节点，关键，需要一个操作符
-
为什么需要 Node 结构？它没有任何行为，它似乎只是一个 int 的冗余包装器。
-
@NeilButterworth 我稍后会充实它，这是临时测试和了解如何以指定方式使用地图的。
-
你不需要
Graph::add_neighbor()中的if语句，你可以无条件地做edge_map[cur_node].push_back(new_node)。
标签： c++ c++11 dictionary struct