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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 <vector>
#include <limits>
#include <cassert>
//[ifdef_macro_function
// Use macro interface to completely disable contract code compilation.
#include <boost/contract_macro.hpp>
int inc(int& x) {
int result;
BOOST_CONTRACT_OLD_PTR(int)(old_x, x);
BOOST_CONTRACT_FUNCTION()
BOOST_CONTRACT_PRECONDITION([&] {
BOOST_CONTRACT_ASSERT(x < std::numeric_limits<int>::max());
})
BOOST_CONTRACT_POSTCONDITION([&] {
BOOST_CONTRACT_ASSERT(x == *old_x + 1);
BOOST_CONTRACT_ASSERT(result == *old_x);
})
;
return result = x++;
}
//]
template<typename T>
class pushable {
friend class boost::contract::access; // Left in code (almost no overhead).
BOOST_CONTRACT_INVARIANT({
BOOST_CONTRACT_ASSERT(capacity() <= max_size());
})
public:
virtual void push_back(
T const& x,
boost::contract::virtual_* v = 0 // Left in code (almost no overhead).
) = 0;
protected:
virtual unsigned capacity() const = 0;
virtual unsigned max_size() const = 0;
};
template<typename T>
void pushable<T>::push_back(T const& x, boost::contract::virtual_* v) {
BOOST_CONTRACT_OLD_PTR(unsigned)(v, old_capacity, capacity());
BOOST_CONTRACT_PUBLIC_FUNCTION(v, this)
BOOST_CONTRACT_PRECONDITION([&] {
BOOST_CONTRACT_ASSERT(capacity() < max_size());
})
BOOST_CONTRACT_POSTCONDITION([&] {
BOOST_CONTRACT_ASSERT(capacity() >= *old_capacity);
})
;
assert(false); // Shall never execute this body.
}
//[ifdef_macro_class
class integers
#define BASES public pushable<int>
:
// Left in code (almost no overhead).
private boost::contract::constructor_precondition<integers>,
BASES
{
// Followings left in code (almost no overhead).
friend class boost::contract::access;
typedef BOOST_CONTRACT_BASE_TYPES(BASES) base_types;
#undef BASES
BOOST_CONTRACT_INVARIANT({
BOOST_CONTRACT_ASSERT(size() <= capacity());
})
public:
integers(int from, int to) :
BOOST_CONTRACT_CONSTRUCTOR_PRECONDITION(integers)([&] {
BOOST_CONTRACT_ASSERT(from <= to);
}),
vect_(to - from + 1)
{
BOOST_CONTRACT_CONSTRUCTOR(this)
BOOST_CONTRACT_POSTCONDITION([&] {
BOOST_CONTRACT_ASSERT(int(size()) == (to - from + 1));
})
;
for(int x = from; x <= to; ++x) vect_.at(x - from) = x;
}
virtual ~integers() {
BOOST_CONTRACT_DESTRUCTOR(this); // Check invariants.
}
virtual void push_back(
int const& x,
boost::contract::virtual_* v = 0 // Left in code (almost no overhead).
) /* override */ {
BOOST_CONTRACT_OLD_PTR(unsigned)(old_size);
BOOST_CONTRACT_PUBLIC_FUNCTION_OVERRIDE(override_push_back)(
v, &integers::push_back, this, x)
BOOST_CONTRACT_PRECONDITION([&] {
BOOST_CONTRACT_ASSERT(size() < max_size());
})
BOOST_CONTRACT_OLD([&] {
old_size = BOOST_CONTRACT_OLDOF(v, size());
})
BOOST_CONTRACT_POSTCONDITION([&] {
BOOST_CONTRACT_ASSERT(size() == *old_size + 1);
})
BOOST_CONTRACT_EXCEPT([&] {
BOOST_CONTRACT_ASSERT(size() == *old_size);
})
;
vect_.push_back(x);
}
private:
BOOST_CONTRACT_OVERRIDE(push_back) // Left in code (almost no overhead).
/* ... */
//]
public: // Could program contracts for these too...
unsigned size() const { return vect_.size(); }
unsigned max_size() const { return vect_.max_size(); }
unsigned capacity() const { return vect_.capacity(); }
private:
std::vector<int> vect_;
};
int main() {
integers i(1, 10);
int x = 123;
i.push_back(inc(x));
assert(x == 124);
assert(i.size() == 11);
return 0;
}
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