C++无法填充C数组的映射

Question

typedef std::map<std::string,int> string2intMap;
typedef string2intMap arrOfMaps[3] ;

//map : string --> array of maps of <std::string,int>
std::map<std::string,arrOfMaps> tryingStuff;

//map : string --> int
string2intMap s;
s["key"]= 100;

tryingStuff["hello"][0] = s;

---

上面的代码没有编译,有问题的行是:tryingStuff ["hello"] [0] = s;

这是编译器大喊:

c:\program files (x86)\microsoft visual studio 10.0\vc\include\map(215): error C2440: '<function-style-cast>' : cannot convert from 'int' to 'std::map<_Kty,_Ty> [3]'
2>          with
2>          [
2>              _Kty=std::string,
2>              _Ty=int
2>          ]
2>          There are no conversions to array types, although there are conversions to references or pointers to arrays
2>          c:\program files (x86)\microsoft visual studio 10.0\vc\include\map(210) : while compiling class template member function 'std::map<_Kty,_Ty> (&std::map<_Kty,arrOfMaps>::operator [](const std::basic_string<_Elem,_Traits,_Ax> &))[3]'
2>          with
2>          [
2>              _Kty=std::string,
2>              _Ty=int,
2>              _Elem=char,
2>              _Traits=std::char_traits<char>,
2>              _Ax=std::allocator<char>
2>          ]
2>          c:\work\toot\tootcode\tootim\tools\doobim\doobim.cpp(95) : see reference to class template instantiation 'std::map<_Kty,_Ty>' being compiled
2>          with
2>          [
2>              _Kty=std::string,
2>              _Ty=arrOfMaps
2>          ]
2>
2>Build FAILED.
2>
2>Time Elapsed 00:00:01.38
========== Build: 1 succeeded, 1 failed, 5 up-to-date, 0 skipped ==========

知道如何让它工作？(我不想改变数据结构,这是一个map:string - > array of maps of)

Answer 1

您不能将C样式数组存储在容器中,因为它们不可分配; 你不能做这个:

int x[3] = { 0, 1, 2 };
int y[3] = { 3, 4, 5 };

x = y;

但是容器需要能够分配/复制它们存储的元素.

考虑使用a std::vector或boost::array^*而不是原始C数组.

_{*这可以std::array在最近的C++标准修订版中找到.}