View Compilation Error

0_0_24474648_7166.cpp: In function 'vi next()':
0_0_24474648_7166.cpp:45:10: error: a function-definition is not allowed here before '{' token
 vi expr(){
          ^
0_0_24474648_7166.cpp:90:1: error: expected '}' at end of input
 }
 ^