foo.cc: In function 'int main()':
foo.cc:37:8: error: overloaded function with no contextual type information
   37 |  end=n-1;
      |        ^
foo.cc:38:8: error: expected primary-expression before 'return'
   38 |  index=return binary_search(a,key,start,end);
      |        ^~~~~~
foo.cc:29:25: warning: unused variable 'enl' [-Wunused-variable]
   29 |  int a[N],n,i,key,start,enl,nid,num=0,index;
      |                         ^~~
foo.cc:29:29: warning: unused variable 'nid' [-Wunused-variable]
   29 |  int a[N],n,i,key,start,enl,nid,num=0,index;
      |                             ^~~
foo.cc:29:33: warning: unused variable 'num' [-Wunused-variable]
   29 |  int a[N],n,i,key,start,enl,nid,num=0,index;
      |                                 ^~~

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