This type contains the functions to return a type with sufficient capacity to hold the result of a given arithmetic operation.

PromotionPolicy

#include <boost/safe_numerics/automatic.hpp>

The following example illustrates the automatic type being passed as a template parameter for the type safe<int>.

#include <boost/safe_numerics/safe_integer.hpp> 
#include <boost/safe_numerics/automatic.hpp>
 
int main(){
    using namespace boost::numeric;
    // use automatic promotion policy where C++ standard arithmetic might lead to incorrect results
    using safe_t = safe<std::int8_t, automatic>;

    // In such cases, there is no runtime overhead from using safe types.
    safe_t x = 127;
    safe_t y = 2;
    auto z = x + y; // z is guarenteed correct without any runtime overhead or interrupt.

    return 0;
}