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#include <stdexcept>
#include <iostream>
#include <array>
#include <boost/safe_numerics/safe_integer_range.hpp>
void detected_msg(bool detected){
std::cout << (detected ? "error detected!" : "error NOT detected! ") << std::endl;
}
int main(int, const char *[]){
// problem: array index values can exceed array bounds
std::cout << "example 5: ";
std::cout << "array index values can exceed array bounds" << std::endl;
std::cout << "Not using safe numerics" << std::endl;
std::array<int, 37> i_array;
// unsigned int i_index = 43;
// the following corrupts memory.
// This may or may not be detected at run time.
// i_array[i_index] = 84; // comment this out so it can be tested!
std::cout << "error NOT detected!" << std::endl;
// solution: replace unsigned array index with safe_unsigned_range
std::cout << "Using safe numerics" << std::endl;
try{
using namespace boost::safe_numerics;
using i_index_t = safe_unsigned_range<0, i_array.size() - 1>;
i_index_t i_index;
i_index = 36; // this works fine
i_array[i_index] = 84;
i_index = 43; // throw exception here!
std::cout << "error NOT detected!" << std::endl; // so we never arrive here
}
catch(const std::exception & e){
std::cout << "error detected:" << e.what() << std::endl;
}
return 0;
}
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