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// 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 <limits>
#include <cassert>
//[introduction
#include <boost/contract.hpp>
void inc(int& x) {
boost::contract::old_ptr<int> old_x = BOOST_CONTRACT_OLDOF(x); // Old value.
boost::contract::check c = boost::contract::function()
.precondition([&] {
BOOST_CONTRACT_ASSERT(x < std::numeric_limits<int>::max()); // Line 17.
})
.postcondition([&] {
BOOST_CONTRACT_ASSERT(x == *old_x + 1); // Line 20.
})
;
++x; // Function body.
}
//]
int main() {
int x = 10;
inc(x);
assert(x == 11);
return 0;
}
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