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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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