Visual Studio 11 compile-time error using std::map
c++, compiler-errors, gcc, visual-studio
Solution
Try `auto z = *x.find(1);` instead. The `[]`-operator requires a default-constructible type. In fact, the entire container requires a default-constructible type, so you really can't expect anything but random luck as you try out various implementations.
Problem
The following code compiles with gcc-4.5.1 but not in Visual Studio 11. ``` #include <map> #include <array> typedef std::pair<const unsigned int, std::array<const unsigned int, 4>> pairus; int main(){ std::map<const unsigned int, std::array<const unsigned int, 4> > x; std::array<const unsigned int, 4> troll = {1, 2, 3, 4}; x.insert(pairus(1, troll)); auto z = x[1]; } ``` 1 is now mapped to `std::array<> troll`. The insertion works well and the program compiles. But, as soon as i try `auto z = x[1]` -> Therefore trying to get the array troll that `1` is mapped to, the program does not compile with the following error: `error C2512: 'std::array<_Ty,_Size>::array'` : no appropriate default constructor available What causes this difference in behavior between gcc and vs11 and how to fix it ? Thanks.