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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
//[cline90_vstack
#include "vector.hpp"
#include <boost/contract.hpp>
#include <boost/optional.hpp>
#include <cassert>
// NOTE: Incomplete contract assertions, addressing only `empty` and `full`.
template<typename T>
class abstract_stack {
public:
abstract_stack() {
boost::contract::check c = boost::contract::constructor(this)
.postcondition([&] {
// AXIOM as empty() cannot actually be checked here to avoid
// calling pure virtual function length() during construction).
BOOST_CONTRACT_ASSERT_AXIOM(empty());
})
;
}
virtual ~abstract_stack() {
boost::contract::check c = boost::contract::destructor(this);
}
bool full() const {
bool result;
boost::contract::check c = boost::contract::public_function(this)
.postcondition([&] {
BOOST_CONTRACT_ASSERT(result == (length() == capacity()));
})
;
return result = (length() == capacity());
}
bool empty() const {
bool result;
boost::contract::check c = boost::contract::public_function(this)
.postcondition([&] {
BOOST_CONTRACT_ASSERT(result = (length() == 0));
})
;
return result = (length() == 0);
}
virtual int length(boost::contract::virtual_* v = 0) const = 0;
virtual int capacity(boost::contract::virtual_* v = 0) const = 0;
virtual T const& item(boost::contract::virtual_* v = 0) const = 0;
virtual void push(T const& value, boost::contract::virtual_* v = 0) = 0;
virtual T const& pop(boost::contract::virtual_* v = 0) = 0;
virtual void clear(boost::contract::virtual_* v = 0) = 0;
};
template<typename T>
int abstract_stack<T>::length(boost::contract::virtual_* v) const {
int result;
boost::contract::check c = boost::contract::public_function(v, result, this)
.postcondition([&] (int const& result) {
BOOST_CONTRACT_ASSERT(result >= 0);
})
;
assert(false);
return result;
}
template<typename T>
int abstract_stack<T>::capacity(boost::contract::virtual_* v) const {
int result;
boost::contract::check c = boost::contract::public_function(v, result, this)
.postcondition([&] (int const& result) {
BOOST_CONTRACT_ASSERT(result >= 0);
})
;
assert(false);
return result;
}
template<typename T>
T const& abstract_stack<T>::item(boost::contract::virtual_* v) const {
boost::optional<T const&> result;
boost::contract::check c = boost::contract::public_function(v, result, this)
.precondition([&] {
BOOST_CONTRACT_ASSERT(!empty());
})
;
assert(false);
return *result;
}
template<typename T>
void abstract_stack<T>::push(T const& value, boost::contract::virtual_* v) {
boost::contract::check c = boost::contract::public_function(v, this)
.precondition([&] {
BOOST_CONTRACT_ASSERT(!full());
})
.postcondition([&] {
BOOST_CONTRACT_ASSERT(!empty());
})
;
assert(false);
}
template<typename T>
T const& abstract_stack<T>::pop(boost::contract::virtual_* v) {
boost::optional<T const&> result;
boost::contract::old_ptr<T> old_item = BOOST_CONTRACT_OLDOF(v, item());
boost::contract::check c = boost::contract::public_function(v, result, this)
.precondition([&] {
BOOST_CONTRACT_ASSERT(!empty());
})
.postcondition([&] (boost::optional<T const&> const& result) {
BOOST_CONTRACT_ASSERT(!full());
BOOST_CONTRACT_ASSERT(*result == *old_item);
})
;
assert(false);
return *result;
}
template<typename T>
void abstract_stack<T>::clear(boost::contract::virtual_* v) {
boost::contract::check c = boost::contract::public_function(v, this)
.postcondition([&] {
BOOST_CONTRACT_ASSERT(empty());
})
;
assert(false);
}
template<typename T>
class vstack
#define BASES private boost::contract::constructor_precondition< \
vstack<T> >, public abstract_stack<T>
: BASES
{
friend class boost::contract::access;
typedef BOOST_CONTRACT_BASE_TYPES(BASES) base_types;
#undef BASES
void invariant() const {
BOOST_CONTRACT_ASSERT(length() >= 0);
BOOST_CONTRACT_ASSERT(length() < capacity());
}
BOOST_CONTRACT_OVERRIDES(length, capacity, item, push, pop, clear)
public:
explicit vstack(int count = 10) :
boost::contract::constructor_precondition<vstack>([&] {
BOOST_CONTRACT_ASSERT(count >= 0);
}),
vect_(count), // OK, executed after precondition so count >= 0.
len_(0)
{
boost::contract::check c = boost::contract::constructor(this)
.postcondition([&] {
BOOST_CONTRACT_ASSERT(length() == 0);
BOOST_CONTRACT_ASSERT(capacity() == count);
})
;
}
virtual ~vstack() {
boost::contract::check c = boost::contract::destructor(this);
}
// Inherited from abstract_stack.
virtual int length(boost::contract::virtual_* v = 0) const /* override */ {
int result;
boost::contract::check c = boost::contract::public_function<
override_length>(v, result, &vstack::length, this);
return result = len_;
}
virtual int capacity(boost::contract::virtual_* v = 0)
const /* override */ {
int result;
boost::contract::check c = boost::contract::public_function<
override_capacity>(v, result, &vstack::capacity, this);
return result = vect_.size();
}
virtual T const& item(boost::contract::virtual_* v = 0)
const /* override */ {
boost::optional<T const&> result;
boost::contract::check c = boost::contract::public_function<
override_item>(v, result, &vstack::item, this);
return *(result = vect_[len_ - 1]);
}
virtual void push(T const& value, boost::contract::virtual_* v = 0)
/* override */ {
boost::contract::check c = boost::contract::public_function<
override_push>(v, &vstack::push, this, value);
vect_[len_++] = value;
}
virtual T const& pop(boost::contract::virtual_* v = 0) /* override */ {
boost::optional<T const&> result;
boost::contract::check c = boost::contract::public_function<
override_pop>(v, result, &vstack::pop, this);
return *(result = vect_[--len_]);
}
virtual void clear(boost::contract::virtual_* v = 0) /* override */ {
boost::contract::check c = boost::contract::public_function<
override_clear>(v, &vstack::clear, this);
len_ = 0;
}
private:
vector<T> vect_;
int len_;
};
int main() {
vstack<int> s(3);
assert(s.capacity() == 3);
s.push(123);
assert(s.length() == 1);
assert(s.pop() == 123);
return 0;
}
//]
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