如何在没有宏的情况下正确使用 NED-Trie？
How to correctly use NED-Trie without macro?
我正在尝试使用 NED-Trie, it only has a single header file。
如何在不使用 NEDTRIE_* 宏的情况下使用这个库？并迭代以从 iterator 中获取键和值？ trie_iterator
上似乎没有 first 和 second 属性
#include <cstring>
#include "nedtrie.h"
#include <iostream>
#include <string>
using namespace std;
typedef nedtries::trie_map<string,double> MSD;
int main() {
MSD m;
m["test"] = 1234;
m["yay"] = 2345;
m["foo"] = 3456;
m["bar"] = 4567;
for(auto it = m.begin(); it != m.end(); ++it) {
string key = it->first;
double val = it->second;
}
}
从错误来看，似乎 trie_map 不能与 std::string?
一起使用
In file included from nedtrie.cpp:2:
./deps/nedtrie.h:1813:20: error: no viable conversion from 'const std::basic_string<char>' to 'size_t' (aka 'unsigned long')
return r->key;
^~~~~~
./deps/nedtrie.h:1625:14: note: in instantiation of member function 'nedtries::intern::findkeyfunct_t<std::basic_string<char>, double, nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>,
std::_List_iterator<unsigned long> >, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double> >::operator()' requested here
return keyfunct_()(*v);
^
./deps/nedtrie.h:611:17: note: in instantiation of function template specialization 'nedtries::intern::to_Ckeyfunct<nedtries::intern::findkeyfunct_t<std::basic_string<char>, double, nedtries::trie_maptype<std::basic_string<char>, double,
nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> >, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double> >, nedtries::trie_maptype<std::basic_string<char>, double,
nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > >' requested here
size_t rkey=keyfunct(r), keybit, nodekey;
^
./deps/nedtrie.h:1898:14: note: in instantiation of function template specialization 'nedtries::triefind<nedtries::trie_map_head<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>,
std::_List_iterator<unsigned long> > >, nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> >, 24, &nedtries::intern::to_Ckeyfunct>' requested here
return triefind<trie_map_head<mapvaluetype>, mapvaluetype, trie_fieldoffset, intern::to_Ckeyfunct<intern::findkeyfunct_t<keytype, type, mapvaluetype, keyfunct> > >(&triehead, (mapvaluetype *) buffer);
^
./deps/nedtrie.h:2069:50: note: in instantiation of member function 'nedtries::trie_map<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::allocator<nedtries::trie_maptype<std::basic_string<char>, double,
nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > >, nedpolicy::nobblezeros, std::list<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>,
double>, std::_List_iterator<unsigned long> >, std::allocator<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > > > >::triehead_find' requested here
mapvaluetype *r=const_cast<mapvaluetype *>(triehead_find(key));
^
nedtrie.cpp:9:8: note: in instantiation of member function 'nedtries::trie_map<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::allocator<nedtries::trie_maptype<std::basic_string<char>, double,
nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > >, nedpolicy::nobblezeros, std::list<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>,
double>, std::_List_iterator<unsigned long> >, std::allocator<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > > > >::operator[]' requested here
m["test"] = 1234;
^
In file included from nedtrie.cpp:2:
./deps/nedtrie.h:1814:18: error: no viable conversion from 'std::basic_string<char>' to 'size_t' (aka 'unsigned long')
return keyfunct()(v);
^~~~~~~~~~~~~
./deps/nedtrie.h:1728:19: warning: unused variable 'ensure_trie_link_offset_is_bounded' [-Wunused-variable]
static char ensure_trie_link_offset_is_bounded[trie_link_offset+sizeof(trie_link)<=sizeof(*this)];
^
./deps/nedtrie.h:1939:76: note: in instantiation of member function 'nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> >::trie_maptype' requested here
iterator it=iterator(this, stlcontainer::insert(stlcontainer::end(), std::move(val)));
^
./deps/nedtrie.h:2075:12: note: in instantiation of member function 'nedtries::trie_map<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::allocator<nedtries::trie_maptype<std::basic_string<char>, double,
nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > >, nedpolicy::nobblezeros, std::list<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>,
double>, std::_List_iterator<unsigned long> >, std::allocator<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > > > >::triehead_insert' requested
here
it=triehead_insert(key, std::move(type()));
^
nedtrie.cpp:9:8: note: in instantiation of member function 'nedtries::trie_map<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::allocator<nedtries::trie_maptype<std::basic_string<char>, double,
nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > >, nedpolicy::nobblezeros, std::list<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>,
double>, std::_List_iterator<unsigned long> >, std::allocator<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > > > >::operator[]' requested here
m["test"] = 1234;
^
In file included from nedtrie.cpp:2:
./deps/nedtrie.h:1625:14: error: no viable conversion from 'std::basic_string<char>' to 'size_t' (aka 'unsigned long')
return keyfunct_()(*v);
^~~~~~~~~~~~~~~
./deps/nedtrie.h:323:17: note: in instantiation of function template specialization 'nedtries::intern::to_Ckeyfunct<nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, nedtries::trie_maptype<std::basic_string<char>, double,
nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > >' requested here
size_t rkey=keyfunct(r), keybit, nodekey;
^
./deps/nedtrie.h:1942:7: note: in instantiation of function template specialization 'nedtries::trieinsert<nedtries::trie_map_head<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>,
std::_List_iterator<unsigned long> > >, nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> >, 24, &nedtries::intern::to_Ckeyfunct>' requested here
trieinsert<trie_map_head<mapvaluetype>, mapvaluetype, trie_fieldoffset, intern::to_Ckeyfunct<keyfunct> >(&triehead, const_cast<mapvaluetype *>(&(*it)));
^
./deps/nedtrie.h:2075:12: note: in instantiation of member function 'nedtries::trie_map<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::allocator<nedtries::trie_maptype<std::basic_string<char>, double,
nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > >, nedpolicy::nobblezeros, std::list<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>,
double>, std::_List_iterator<unsigned long> >, std::allocator<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > > > >::triehead_insert' requested
here
it=triehead_insert(key, std::move(type()));
^
nedtrie.cpp:9:8: note: in instantiation of member function 'nedtries::trie_map<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::allocator<nedtries::trie_maptype<std::basic_string<char>, double,
nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > >, nedpolicy::nobblezeros, std::list<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>,
double>, std::_List_iterator<unsigned long> >, std::allocator<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > > > >::operator[]' requested here
m["test"] = 1234;
^
In file included from nedtrie.cpp:2:
./deps/nedtrie.h:1773:9: error: no matching function for call to 'trienext'
trienext<trie_map_head<mapvaluetype>, mapvaluetype, mapvaluetype::trie_link_offset, intern::to_Ckeyfunct<typename mapvaluetype::trie_keyfunct_type> >(&parent->triehead, (mapvaluetype *)(&**this)) :
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
nedtrie.cpp:13:47: note: in instantiation of member function 'nedtries::trie_iterator<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::allocator<nedtries::trie_maptype<std::basic_string<char>, double,
nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > >, nobblezeros, std::list<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>,
std::_List_iterator<unsigned long> >, std::allocator<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > > >,
std::_List_iterator<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > >, 1, nedtries::trie_maptype<std::basic_string<char>, double,
nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> >, nedtries::trie_iterator<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>,
std::allocator<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > >, nobblezeros, std::list<nedtries::trie_maptype<std::basic_string<char>, double,
nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> >, std::allocator<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>,
std::_List_iterator<unsigned long> > > >, std::_List_const_iterator<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > >, 1,
nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> >,
nedtries::intern::noconstiteratortype<std::_List_const_iterator<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > > > > >::operator++' requested
here
for(auto it = m.begin(); it != m.end(); ++it) {
^
./deps/nedtrie.h:1141:120: note: candidate template ignored: invalid explicitly-specified argument for template parameter 'keyfunct'
template<class trietype, class type, size_t fieldoffset, size_t (*keyfunct)(const type *RESTRICT)> DEBUGINLINE type *trienext(const trietype *RESTRICT head, const type *RESTRICT r)
^
1 warning and 4 errors generated.
免责声明：我是 nedtries 的作者。你应该用 nedtries 标记这个问题，然后我会更快地看到它。
除了 size_t 之外，您不能使用任何东西作为 trie_map 中的键，因为底层 C 宏实现仅适用于 size_t 键。这是因为它依赖于位扫描 CPU 操作码，而这些操作码采用 size_t。如果 IEEE 754 是一种稳定的二进制格式，您 可以 通过将其转换为 size_t 来将其与双精度一起使用，但如果 IEEE 754 不是稳定的二进制格式，则您无法安全地执行此操作。
如文档所述，通过 std::hash 传递任何非 size_t 键并在取消引用后检查冲突。关于trie_map没有提供第一和第二，嗯trie_map是一堆垃圾代码。我确实在文档中说过不要使用它。如果你检查源代码，你会发现我做了很多非法和未定义的行为，所有这些都是你应该避免在你的代码库中出现的东西。也就是说，作为 "what if?" 场景的快速原型，特别是 "will bitwise tries really help out my C++ code here?"，它符合要求。
Boost C++ 库已经在 Trie STL 容器上完成了一些工作，最近一次是在 GSoC 2013 中。不过还没有准备好生产。很遗憾，因为 C++ 真的可以用适当的 trie STL 容器来做。
尼尔
我正在尝试使用 NED-Trie, it only has a single header file。
如何在不使用 NEDTRIE_* 宏的情况下使用这个库？并迭代以从 iterator 中获取键和值？ trie_iterator
first 和 second 属性
#include <cstring>
#include "nedtrie.h"
#include <iostream>
#include <string>
using namespace std;
typedef nedtries::trie_map<string,double> MSD;
int main() {
MSD m;
m["test"] = 1234;
m["yay"] = 2345;
m["foo"] = 3456;
m["bar"] = 4567;
for(auto it = m.begin(); it != m.end(); ++it) {
string key = it->first;
double val = it->second;
}
}
从错误来看，似乎 trie_map 不能与 std::string?
In file included from nedtrie.cpp:2:
./deps/nedtrie.h:1813:20: error: no viable conversion from 'const std::basic_string<char>' to 'size_t' (aka 'unsigned long')
return r->key;
^~~~~~
./deps/nedtrie.h:1625:14: note: in instantiation of member function 'nedtries::intern::findkeyfunct_t<std::basic_string<char>, double, nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>,
std::_List_iterator<unsigned long> >, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double> >::operator()' requested here
return keyfunct_()(*v);
^
./deps/nedtrie.h:611:17: note: in instantiation of function template specialization 'nedtries::intern::to_Ckeyfunct<nedtries::intern::findkeyfunct_t<std::basic_string<char>, double, nedtries::trie_maptype<std::basic_string<char>, double,
nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> >, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double> >, nedtries::trie_maptype<std::basic_string<char>, double,
nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > >' requested here
size_t rkey=keyfunct(r), keybit, nodekey;
^
./deps/nedtrie.h:1898:14: note: in instantiation of function template specialization 'nedtries::triefind<nedtries::trie_map_head<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>,
std::_List_iterator<unsigned long> > >, nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> >, 24, &nedtries::intern::to_Ckeyfunct>' requested here
return triefind<trie_map_head<mapvaluetype>, mapvaluetype, trie_fieldoffset, intern::to_Ckeyfunct<intern::findkeyfunct_t<keytype, type, mapvaluetype, keyfunct> > >(&triehead, (mapvaluetype *) buffer);
^
./deps/nedtrie.h:2069:50: note: in instantiation of member function 'nedtries::trie_map<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::allocator<nedtries::trie_maptype<std::basic_string<char>, double,
nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > >, nedpolicy::nobblezeros, std::list<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>,
double>, std::_List_iterator<unsigned long> >, std::allocator<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > > > >::triehead_find' requested here
mapvaluetype *r=const_cast<mapvaluetype *>(triehead_find(key));
^
nedtrie.cpp:9:8: note: in instantiation of member function 'nedtries::trie_map<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::allocator<nedtries::trie_maptype<std::basic_string<char>, double,
nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > >, nedpolicy::nobblezeros, std::list<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>,
double>, std::_List_iterator<unsigned long> >, std::allocator<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > > > >::operator[]' requested here
m["test"] = 1234;
^
In file included from nedtrie.cpp:2:
./deps/nedtrie.h:1814:18: error: no viable conversion from 'std::basic_string<char>' to 'size_t' (aka 'unsigned long')
return keyfunct()(v);
^~~~~~~~~~~~~
./deps/nedtrie.h:1728:19: warning: unused variable 'ensure_trie_link_offset_is_bounded' [-Wunused-variable]
static char ensure_trie_link_offset_is_bounded[trie_link_offset+sizeof(trie_link)<=sizeof(*this)];
^
./deps/nedtrie.h:1939:76: note: in instantiation of member function 'nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> >::trie_maptype' requested here
iterator it=iterator(this, stlcontainer::insert(stlcontainer::end(), std::move(val)));
^
./deps/nedtrie.h:2075:12: note: in instantiation of member function 'nedtries::trie_map<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::allocator<nedtries::trie_maptype<std::basic_string<char>, double,
nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > >, nedpolicy::nobblezeros, std::list<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>,
double>, std::_List_iterator<unsigned long> >, std::allocator<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > > > >::triehead_insert' requested
here
it=triehead_insert(key, std::move(type()));
^
nedtrie.cpp:9:8: note: in instantiation of member function 'nedtries::trie_map<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::allocator<nedtries::trie_maptype<std::basic_string<char>, double,
nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > >, nedpolicy::nobblezeros, std::list<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>,
double>, std::_List_iterator<unsigned long> >, std::allocator<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > > > >::operator[]' requested here
m["test"] = 1234;
^
In file included from nedtrie.cpp:2:
./deps/nedtrie.h:1625:14: error: no viable conversion from 'std::basic_string<char>' to 'size_t' (aka 'unsigned long')
return keyfunct_()(*v);
^~~~~~~~~~~~~~~
./deps/nedtrie.h:323:17: note: in instantiation of function template specialization 'nedtries::intern::to_Ckeyfunct<nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, nedtries::trie_maptype<std::basic_string<char>, double,
nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > >' requested here
size_t rkey=keyfunct(r), keybit, nodekey;
^
./deps/nedtrie.h:1942:7: note: in instantiation of function template specialization 'nedtries::trieinsert<nedtries::trie_map_head<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>,
std::_List_iterator<unsigned long> > >, nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> >, 24, &nedtries::intern::to_Ckeyfunct>' requested here
trieinsert<trie_map_head<mapvaluetype>, mapvaluetype, trie_fieldoffset, intern::to_Ckeyfunct<keyfunct> >(&triehead, const_cast<mapvaluetype *>(&(*it)));
^
./deps/nedtrie.h:2075:12: note: in instantiation of member function 'nedtries::trie_map<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::allocator<nedtries::trie_maptype<std::basic_string<char>, double,
nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > >, nedpolicy::nobblezeros, std::list<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>,
double>, std::_List_iterator<unsigned long> >, std::allocator<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > > > >::triehead_insert' requested
here
it=triehead_insert(key, std::move(type()));
^
nedtrie.cpp:9:8: note: in instantiation of member function 'nedtries::trie_map<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::allocator<nedtries::trie_maptype<std::basic_string<char>, double,
nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > >, nedpolicy::nobblezeros, std::list<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>,
double>, std::_List_iterator<unsigned long> >, std::allocator<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > > > >::operator[]' requested here
m["test"] = 1234;
^
In file included from nedtrie.cpp:2:
./deps/nedtrie.h:1773:9: error: no matching function for call to 'trienext'
trienext<trie_map_head<mapvaluetype>, mapvaluetype, mapvaluetype::trie_link_offset, intern::to_Ckeyfunct<typename mapvaluetype::trie_keyfunct_type> >(&parent->triehead, (mapvaluetype *)(&**this)) :
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
nedtrie.cpp:13:47: note: in instantiation of member function 'nedtries::trie_iterator<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::allocator<nedtries::trie_maptype<std::basic_string<char>, double,
nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > >, nobblezeros, std::list<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>,
std::_List_iterator<unsigned long> >, std::allocator<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > > >,
std::_List_iterator<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > >, 1, nedtries::trie_maptype<std::basic_string<char>, double,
nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> >, nedtries::trie_iterator<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>,
std::allocator<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > >, nobblezeros, std::list<nedtries::trie_maptype<std::basic_string<char>, double,
nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> >, std::allocator<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>,
std::_List_iterator<unsigned long> > > >, std::_List_const_iterator<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > >, 1,
nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> >,
nedtries::intern::noconstiteratortype<std::_List_const_iterator<nedtries::trie_maptype<std::basic_string<char>, double, nedtries::trie_maptype_keyfunct<std::basic_string<char>, double>, std::_List_iterator<unsigned long> > > > > >::operator++' requested
here
for(auto it = m.begin(); it != m.end(); ++it) {
^
./deps/nedtrie.h:1141:120: note: candidate template ignored: invalid explicitly-specified argument for template parameter 'keyfunct'
template<class trietype, class type, size_t fieldoffset, size_t (*keyfunct)(const type *RESTRICT)> DEBUGINLINE type *trienext(const trietype *RESTRICT head, const type *RESTRICT r)
^
1 warning and 4 errors generated.
免责声明：我是 nedtries 的作者。你应该用 nedtries 标记这个问题，然后我会更快地看到它。
除了 size_t 之外，您不能使用任何东西作为 trie_map 中的键，因为底层 C 宏实现仅适用于 size_t 键。这是因为它依赖于位扫描 CPU 操作码，而这些操作码采用 size_t。如果 IEEE 754 是一种稳定的二进制格式，您 可以 通过将其转换为 size_t 来将其与双精度一起使用，但如果 IEEE 754 不是稳定的二进制格式，则您无法安全地执行此操作。
如文档所述，通过 std::hash 传递任何非 size_t 键并在取消引用后检查冲突。关于trie_map没有提供第一和第二，嗯trie_map是一堆垃圾代码。我确实在文档中说过不要使用它。如果你检查源代码，你会发现我做了很多非法和未定义的行为，所有这些都是你应该避免在你的代码库中出现的东西。也就是说，作为 "what if?" 场景的快速原型，特别是 "will bitwise tries really help out my C++ code here?"，它符合要求。
Boost C++ 库已经在 Trie STL 容器上完成了一些工作，最近一次是在 GSoC 2013 中。不过还没有准备好生产。很遗憾，因为 C++ 真的可以用适当的 trie STL 容器来做。
尼尔