View Compilation Error

0_0_34102170_26419.cpp: In instantiation of 'matrix<T, N>::matrix(const std::initializer_list<_Tp>&) [with T = int; long long unsigned int N = 4ull]':
0_0_34102170_26419.cpp:88:13:   required from here
0_0_34102170_26419.cpp:28:40: error: array must be initialized with a brace-enclosed initializer
   matrix(const initializer_list<T> &l) {
                                        ^
0_0_34102170_26419.cpp: In instantiation of 'matrix<T, N>::matrix(int) [with T = int; long long unsigned int N = 4ull]':
0_0_34102170_26419.cpp:71:9:   required from 'T power(T, long long int) [with T = matrix<int, 4ull>]'
0_0_34102170_26419.cpp:92:38:   required from here
0_0_34102170_26419.cpp:21:21: error: array must be initialized with a brace-enclosed initializer
   matrix(int v = 0) {
                     ^