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Character Array as a value in C++ map

I want to define something like

Map<int, char[5] > myMap;

The above declaration is accepted by c++ compiler and no error is thrown but when I do something like this

int main()
{
    char arr[5] ="sdf";
    map <int, char[5]> myMap;
    myMap.insert(pair<int, char[5]>(0,arr));
    return 0;
}

I get error as:

In file included from /usr/include/c++/4.6/bits/stl_algobase.h:65:0,
                 from /usr/include/c++/4.6/bits/char_traits.h:41,
                 from /usr/include/c++/4.6/ios:41,
                 from /usr/include/c++/4.6/ostream:40,
                 from /usr/include/c++/4.6/iostream:40,
                 from charMap.cpp:1:
/usr/include/c++/4.6/bits/stl_pair.h: In constructor ‘std::pair<_T1, _T2>::pair(const _T1&, const _T2&) [with _T1 = int, _T2 = char [5]]’:
charMap.cpp:9:42:   instantiated from here
/usr/include/c++/4.6/bits/stl_pair.h:104:31: error: array used as initializer
/usr/include/c++/4.6/bits/stl_pair.h: In constructor ‘std::pair<_T1, _T2>::pair(const std::pair<_U1, _U2>&) [with _U1 = int, _U2 = char [5], _T1 = const int, _T2 = char [5]]’:
charMap.cpp:9:43:   instantiated from here
/usr/include/c++/4.6/bits/stl_pair.h:109:39: error: array used as initializer

It is important for me to define a fixed size character array because it optimizes my network stream operation. Is there any way to achieve it? I do not want to use char * or std::string.

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Master Oogway Avatar asked Jul 16 '12 17:07

Master Oogway


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1 Answers

I understand your performance requirements (since I do similar things too), but using character arrays in that way is rather unsafe.

If you have access to C++11 you could use std::array. Then you could define your map like:

map <int, array<char, 5>> myMap;

If you cannot use C++11, then you could use boost::array.

like image 114
betabandido Avatar answered Oct 05 '22 17:10

betabandido