90 lines
2.8 KiB
C++
90 lines
2.8 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 <cassert>
|
|
|
|
template<typename T>
|
|
class pushable { // Somewhat arbitrary base (used just to show subcontracting).
|
|
public:
|
|
void invariant() const {
|
|
BOOST_CONTRACT_ASSERT(capacity() <= max_size());
|
|
}
|
|
|
|
virtual void push_back(T const& value,
|
|
boost::contract::virtual_* v = 0) = 0; // Pure virtual function.
|
|
|
|
protected:
|
|
virtual unsigned capacity() const = 0;
|
|
virtual unsigned max_size() const = 0;
|
|
};
|
|
|
|
template<typename T> // Contract for pure virtual function.
|
|
void pushable<T>::push_back(T const& value, boost::contract::virtual_* v) {
|
|
boost::contract::old_ptr<unsigned> old_capacity =
|
|
BOOST_CONTRACT_OLDOF(v, capacity());
|
|
boost::contract::check c = boost::contract::public_function(v, this)
|
|
.precondition([&] {
|
|
BOOST_CONTRACT_ASSERT(capacity() < max_size());
|
|
})
|
|
.postcondition([&] {
|
|
BOOST_CONTRACT_ASSERT(capacity() >= *old_capacity);
|
|
})
|
|
;
|
|
assert(false); // Shall never execute this body.
|
|
}
|
|
|
|
//[introduction_public
|
|
template<typename T>
|
|
class vector
|
|
#define BASES public pushable<T>
|
|
: BASES
|
|
{
|
|
public:
|
|
typedef BOOST_CONTRACT_BASE_TYPES(BASES) base_types; // For subcontracting.
|
|
#undef BASES
|
|
|
|
void invariant() const { // Checked in AND with base class invariants.
|
|
BOOST_CONTRACT_ASSERT(size() <= capacity());
|
|
}
|
|
|
|
virtual void push_back(T const& value,
|
|
boost::contract::virtual_* v = 0) /* override */ { // For virtuals.
|
|
boost::contract::old_ptr<unsigned> old_size =
|
|
BOOST_CONTRACT_OLDOF(v, size()); // Old values for virtuals.
|
|
boost::contract::check c = boost::contract::public_function< // For overrides.
|
|
override_push_back>(v, &vector::push_back, this, value)
|
|
.precondition([&] { // Checked in OR with base preconditions.
|
|
BOOST_CONTRACT_ASSERT(size() < max_size());
|
|
})
|
|
.postcondition([&] { // Checked in AND with base postconditions.
|
|
BOOST_CONTRACT_ASSERT(size() == *old_size + 1);
|
|
})
|
|
;
|
|
|
|
vect_.push_back(value);
|
|
}
|
|
BOOST_CONTRACT_OVERRIDE(push_back) // Define `override_push_back` above.
|
|
|
|
// Could program contracts for those as well.
|
|
unsigned size() const { return vect_.size(); }
|
|
unsigned max_size() const { return vect_.max_size(); }
|
|
unsigned capacity() const { return vect_.capacity(); }
|
|
|
|
private:
|
|
std::vector<T> vect_;
|
|
};
|
|
//]
|
|
|
|
int main() {
|
|
vector<int> vect;
|
|
vect.push_back(123);
|
|
assert(vect.size() == 1);
|
|
return 0;
|
|
}
|
|
|