View Compilation Error

1_728_5821_29681.cpp: In function 'void sol2(std::string)':
1_728_5821_29681.cpp:61:41: error: conversion from 'void' to non-scalar type 'std::string {aka std::basic_string<char>}' requested
  string as2=reverse(as.begin(), as.end());
                                         ^