我有以下代码,但“int age”似乎有问题,代码如下:
struct MyStruct
{
char* firstName;
char* secondName;
int age;
};
typedef composite_key
<MyStruct*,
BOOST_MULTI_INDEX_MEMBER(MyStruct, char*, firstName),
BOOST_MULTI_INDEX_MEMBER(MyStruct, char*, secondName),
BOOST_MULTI_INDEX_MEMBER(MyStruct, int, age)
> comp_key;
struct CompareLess
{ // functor for operator<=
static inline int compare(const char* left, const char* right)
{
return strcmp(left, right);
}
inline bool operator()(const char* left, const char* right) const
{ // apply operator<= to operands
return compare(left, right)<0;
}
static inline int compare(const MyStruct* myStruct1, const MyStruct* myStruct2)
{
int result= compare(myStruct1->firstName, myStruct2->firstName);
if(result!=0)
return result;
else
{
return compare(myStruct2->secondName, myStruct2->secondName);
}
}
inline bool operator()(const MyStruct* myStruct1, const MyStruct* myStruct2)
{
return compare(myStruct1, myStruct2)<0;
}
};
typedef multi_index_container
<
MyStruct*,
indexed_by
<
ordered_unique
<
comp_key,
/*CompareLess*/
composite_key_compare
<
CompareLess,
CompareLess,
std::less<int>
>
>
>
> MyContainer;
boost::ptr_vector<MyStruct> vec;
MyStruct* struct1=new MyStruct();
struct1->firstName="Michael";
struct1->secondName="Mike";
struct1->age=20;
vec.push_back(struct1);
MyContainer myContainer;
myContainer.insert(struct1);
char* first="Michael";
char* second="Mike";
string michael="Michael";
auto it=myContainer.find(boost::make_tuple(michael.c_str(), (const char*)second,20);
if(it!=myContainer.end())
cout << (*it)->age << endl;
问题出在 '(boost::make_tuple(michael.c_str(), (const char*)second),20)' 上,它似乎不能接受 '20'。详细错误如下:
C:\boost_1_52\boost/multi_index/composite_key.hpp(381): 错误 C3849: 对类型为“int”的表达式的函数式调用将丢失所有 3 个可用运算符重载的 const 和/或 volatile 限定符 1> C:\ boost_1_52\boost/multi_index/composite_key.hpp(380) : 在编译类模板成员函数'bool boost::multi_index::detail::compare_ckey_ckey_normal::compare(const KeyCons1 &,const Value1 &,const KeyCons2 &,const Value2 & ,const CompareCons &)'
有没有办法解决这个问题?