| 54 | |
| 55 | |
| 56 | int main() |
| 57 | { |
| 58 | // Exercise print_answer a few times and handle errors. Note that the |
| 59 | // exception objects that compute_answer_throws throws are not handled as |
| 60 | // exceptions, but as regular LEAF error error objects... |
| 61 | for( int i=0; i!=42; ++i ) |
| 62 | { |
| 63 | leaf::try_handle_all( |
| 64 | []() -> leaf::result<void> |
| 65 | { |
| 66 | BOOST_LEAF_CHECK(print_answer()); |
| 67 | return { }; |
| 68 | }, |
| 69 | |
| 70 | []( error_a const & ) |
| 71 | { |
| 72 | std::cerr << "Error A!" << std::endl; |
| 73 | }, |
| 74 | |
| 75 | []( error_b const & ) |
| 76 | { |
| 77 | std::cerr << "Error B!" << std::endl; |
| 78 | }, |
| 79 | |
| 80 | // ...except for error_c errors, which (for demonstration) are |
| 81 | // captured as exceptions into std::exception_ptr as "unknown" |
| 82 | // exceptions. Presumably this should not happen, therefore at this |
| 83 | // point we treat this situation as a logic error: we print |
| 84 | // diagnostic information and bail out. |
| 85 | []( std::exception_ptr const * ep ) |
| 86 | { |
| 87 | std::cerr << "Got unknown error!" << std::endl; |
| 88 | |
| 89 | // Above, why do we take ep as a pointer? Because handle_all |
| 90 | // requires that the last handler matches any error and, taken |
| 91 | // as a pointer, if there isn't a std::exception_ptr associated |
| 92 | // with the error, the handler will still be matched (with 0 |
| 93 | // passed for ep). Had we taken it by value or by const &, the |
| 94 | // program would not have compiled. |
| 95 | if( ep ) |
| 96 | leaf::try_catch( |
| 97 | [&] |
| 98 | { |
| 99 | std::rethrow_exception(*ep); |
| 100 | }, |
| 101 | []( leaf::error_info const & unmatched ) |
| 102 | { |
| 103 | std::cerr << unmatched; |
| 104 | } ); |
| 105 | } ); |
| 106 | } |
| 107 | |
| 108 | return 0; |
| 109 | } |
nothing calls this directly
no test coverage detected