libs/contract/example/features/code_block.cpp
// 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);
int total = 10;
//[code_block
/* ... */
// Contract for a code block.
{ // Code block entry (check preconditions).
boost::contract::old_ptr<int> old_total = BOOST_CONTRACT_OLDOF(total);
boost::contract::check c = boost::contract::function()
.precondition([&] {
BOOST_CONTRACT_ASSERT(v.size() == 3);
})
.postcondition([&] {
BOOST_CONTRACT_ASSERT(total == *old_total + v[0] + v[1] + v[2]);
})
;
total += v[0] + v[1] + v[2]; // Code block body.
} // Code block exit (check postconditions and exceptions guarantees).
/* ... */
//]
assert(total == 16);
return 0;
}