View Compilation Error

0_0_36986643_21906.cpp: In function 'void {anonymous}::solve()':
0_0_36986643_21906.cpp:135:22: error: expected unqualified-id before '[' token
                 auto [l, r] = get_tangent(cv, p[i]);
                      ^
0_0_36986643_21906.cpp:137:33: error: 'l' was not declared in this scope
                 s1.push_back(cv[l]);
                                 ^
0_0_36986643_21906.cpp:138:33: error: 'r' was not declared in this scope
                 s1.push_back(cv[r]);
                                 ^