Files
contract/example/n1962/sqrt.cpp
2016-05-12 08:22:34 -07:00

28 lines
579 B
C++

//[n1962_sqrt
#include <boost/contract.hpp>
#include <cmath>
#include <cassert>
double mysqrt(double x, double precision = 1e-6) {
double result;
boost::contract::guard c = boost::contract::function()
.precondition([&] {
BOOST_CONTRACT_ASSERT(x >= 0.0);
})
.postcondition([&] {
BOOST_CONTRACT_ASSERT(fabs(result * result - x) <= precision);
})
;
return result = sqrt(x);
}
int main() {
double const precision = 1e-6;
assert(fabs(mysqrt(4.0, precision) - 2.0) <= precision);
return 0;
}
//]