foo.cc: In function ‘int main()’:
foo.cc:11:10: error: ‘generate_n’ is not a member of ‘std’
   11 |     std::generate_n(dp.begin()+2, n-1, [&,i=1]() mutable {
      |          ^~~~~~~~~~
foo.cc:11:43: warning: lambda capture initializers only available with ‘-std=c++14’ or ‘-std=gnu++14’ [-Wc++14-extensions]
   11 |     std::generate_n(dp.begin()+2, n-1, [&,i=1]() mutable {
      |                                           ^
foo.cc: In lambda function:
foo.cc:12:22: warning: value computed is not used [-Wunused-value]
   12 |         return dp[i] + dp[i-1], i++; });