contract/example/features/loop.cpp

41 lines
1.1 KiB
C++

// Copyright (C) 2008-2018 Lorenzo Caminiti
// Distributed under the Boost Software License, Version 1.0 (see accompanying
// file LICENSE_1_0.txt or a copy at http://www.boost.org/LICENSE_1_0.txt).
// See: http://www.boost.org/doc/libs/release/libs/contract/doc/html/index.html
#include <boost/contract.hpp>
#include <vector>
#include <algorithm>
#include <limits>
int main() {
std::vector<int> v;
v.push_back(1);
v.push_back(2);
v.push_back(3);
//[loop
int total = 0;
// Contract for a for-loop (same for while- and all other loops).
for(std::vector<int>::const_iterator i = v.begin(); i != v.end(); ++i) {
boost::contract::old_ptr<int> old_total = BOOST_CONTRACT_OLDOF(total);
boost::contract::check c = boost::contract::function()
.precondition([&] {
BOOST_CONTRACT_ASSERT(
total < std::numeric_limits<int>::max() - *i);
})
.postcondition([&] {
BOOST_CONTRACT_ASSERT(total == *old_total + *i);
})
;
total += *i; // For-loop body.
}
//]
assert(total == 6);
return 0;
}