View Compilation Error

0_0_36979163_22958.cpp: In function 'void addedge(int, int, int, int)':
0_0_36979163_22958.cpp:39:21: error: could not convert '{x, y, a, b}' from '<brace-enclosed initializer list>' to 'edge'
     edge ed={x,y,a,b};
                     ^