View Compilation Error

0_0_38337257_5821.cpp:37:34: error: 'nve' function uses 'auto' type specifier without trailing return type
 auto nve(size_t n, Args &&...args) {
                                  ^
0_0_38337257_5821.cpp:37:34: note: deduced return type only available with -std=c++1y or -std=gnu++1y
0_0_38337257_5821.cpp: In function 'auto nve(size_t, Args&& ...)':
0_0_38337257_5821.cpp:38:6: error: expected '(' before 'constexpr'
   if constexpr (sizeof...(args) == 1) {
      ^
0_0_38337257_5821.cpp:40:5: error: 'else' without a previous 'if'
   } else {
     ^
0_0_38337257_5821.cpp:41:18: error: missing template arguments before '(' token
     return vector(n, nve(args...));
                  ^