foo.cc: In function 'int main()':
foo.cc:34:19: error: use of 'auto' in lambda parameter declaration only available with '-std=c++14' or '-std=gnu++14'
   34 |     auto oo = [&](auto x, char c = 10) {
      |                   ^~~~

[Hydro](https://hydro.ac)提供评测服务