Set jump exceptions may be viewed as C-style exceptions. Like C++-style exceptions, set jump exceptions provide the user with the ability to set a place in the code to return to in the event of an error, and a method for generating the exception that performs the jump. The following code example demonstrates this:
#include <cstring>#include <csetjmp>#include <iostream>std::jmp_buf jb;void myfunc(int val){ if (val == 42) { errno = EINVAL; // Invalid argument std::longjmp(jb, -42); }}int main(){ if (setjmp(jb) == -42) { std::cout << "failure: " << strerror(errno) << '\n'; std::exit(EXIT_FAILURE); } myfunc(1); std::cout << "success\n"; myfunc(42); std::cout << "success\n";}// > g++ -std=c++17 scratchpad.cpp; ...
