2021-10-05 21:37:46 +02:00

65 lines
2.0 KiB
C++

// Copyright (c) 2018 Robert Ramey
//
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
#include <exception>
#include <iostream>
#include <type_traits>
#include <boost/safe_numerics/safe_integer.hpp>
#include <boost/safe_numerics/safe_integer_range.hpp>
#include <boost/safe_numerics/safe_integer_literal.hpp>
#include <boost/safe_numerics/utility.hpp>
using namespace boost::safe_numerics;
int main(){
safe_unsigned_range<7, 24> i;
// since the range is included in [0,255], the underlying type of i
// will be an unsigned char.
try{
i = 0; // throws out_of_range exception
std::cout << "fails to detect erroneous assignment" << std::endl;
}
catch(std::exception & e){
// should arrive here
}
try{
i = 9; // ok - no exception expected
}
catch(std::exception & e){
std::cout << "erroneous error for legal assignment" << std::endl;
}
try{
i *= 9; // fails to compile because result can't fin in range
std::cout << "fails to out of range result" << std::endl;
}
catch(std::exception & e){
// should arrive here
}
try{
i = -1; // throws out_of_range exception
std::cout << "fails to detect erroneous assignment" << std::endl;
}
catch(std::exception & e){
// should arrive here
}
std::uint8_t j = 4;
auto k = i + j;
// if either or both types are safe types, the result is a safe type
// determined by promotion policy. In this instance
// the range of i is [7, 24] and the range of j is [0,255].
// so the type of k will be a safe type with a range of [7,279]
static_assert(
is_safe<decltype(k)>::value
&& std::numeric_limits<decltype(k)>::min() == 7
&& std::numeric_limits<decltype(k)>::max() == 279,
"k is a safe range of [7,279]"
);
return 0;
}