静态常量整数成员在class内部直接初始化

 1 #include <vector>
 2 #include <deque>
 3 #include <algorithm>
 4 #include <iostream>
 5 #include <ostream>
 6 #include <iterator>
 7 using namespace std;
 8 template <typename T>
 9 class conststaticconstant
10 {
11 public://class内含const static integral data(整数型别) member,那么就可以直接赋初值
12     static const int _datai = 5;
13     static const long _datal = 3L;
14     static const char _datac = ‘c‘;
15     //static const double _datad = 8.88;//error: ‘constexpr‘ needed for in-class initialization of static data member ‘const float conststaticconstant<T>::_dataf‘ of non-integral type [-fpermissive]
16     //static const float _dataf = 9.9;
17 //    void operator ()(const T& elem){
18 //        cout << elem << ‘ ‘;
19 //    }
20 };
21 int main( )
22 {
23     cout << conststaticconstant<int>::_datai << endl;
24     cout << conststaticconstant<int>::_datal << endl;
25     cout << conststaticconstant<int>::_datac << endl;
26     return 0;
27 }