146 lines
3.9 KiB
C++
146 lines
3.9 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 <limits>
|
|
#include <cassert>
|
|
|
|
//[private_protected_virtual_counter
|
|
class counter {
|
|
// Virtual private and protected functions still declare extra
|
|
// `virtual_* = 0` parameter (otherwise they cannot be overridden), but...
|
|
protected:
|
|
virtual void set(int n, boost::contract::virtual_* = 0) {
|
|
boost::contract::check c = boost::contract::function() // ...no `v`.
|
|
.precondition([&] {
|
|
BOOST_CONTRACT_ASSERT(n <= 0);
|
|
})
|
|
.postcondition([&] {
|
|
BOOST_CONTRACT_ASSERT(get() == n);
|
|
})
|
|
;
|
|
|
|
n_ = n;
|
|
}
|
|
|
|
private:
|
|
virtual void dec(boost::contract::virtual_* = 0) {
|
|
boost::contract::old_ptr<int> old_get = BOOST_CONTRACT_OLDOF(get()); // ...no `v`.
|
|
boost::contract::check c = boost::contract::function() // ...no `v`.
|
|
.precondition([&] {
|
|
BOOST_CONTRACT_ASSERT(
|
|
get() + 1 >= std::numeric_limits<int>::min());
|
|
})
|
|
.postcondition([&] {
|
|
BOOST_CONTRACT_ASSERT(get() == *old_get - 1);
|
|
})
|
|
;
|
|
|
|
set(get() - 1);
|
|
}
|
|
|
|
int n_;
|
|
|
|
/* ... */
|
|
//]
|
|
|
|
public:
|
|
virtual int get(boost::contract::virtual_* v = 0) const {
|
|
int result;
|
|
boost::contract::check c = boost::contract::public_function(
|
|
v, result, this)
|
|
.postcondition([&] (int const result) {
|
|
BOOST_CONTRACT_ASSERT(result <= 0);
|
|
BOOST_CONTRACT_ASSERT(result == n_);
|
|
})
|
|
;
|
|
|
|
return result = n_;
|
|
}
|
|
|
|
counter() : n_(0) {} // Should contract constructor and destructor too.
|
|
|
|
void invariant() const {
|
|
BOOST_CONTRACT_ASSERT(get() <= 0);
|
|
}
|
|
|
|
friend int main();
|
|
};
|
|
|
|
//[private_protected_virtual_counter10
|
|
class counter10
|
|
#define BASES public counter
|
|
: BASES
|
|
{
|
|
public:
|
|
typedef BOOST_CONTRACT_BASE_TYPES(BASES) base_types;
|
|
#undef BASES
|
|
|
|
// Overriding from non-public members so no subcontracting, no override_...
|
|
|
|
virtual void set(int n, boost::contract::virtual_* v = 0) /* override */ {
|
|
boost::contract::check c = boost::contract::public_function(v, this)
|
|
.precondition([&] {
|
|
BOOST_CONTRACT_ASSERT(n % 10 == 0);
|
|
})
|
|
.postcondition([&] {
|
|
BOOST_CONTRACT_ASSERT(get() == n);
|
|
})
|
|
;
|
|
|
|
counter::set(n);
|
|
}
|
|
|
|
virtual void dec(boost::contract::virtual_* v = 0) /* override */ {
|
|
boost::contract::old_ptr<int> old_get = BOOST_CONTRACT_OLDOF(v, get());
|
|
boost::contract::check c = boost::contract::public_function(v, this)
|
|
.precondition([&] {
|
|
BOOST_CONTRACT_ASSERT(
|
|
get() + 10 >= std::numeric_limits<int>::min());
|
|
})
|
|
.postcondition([&] {
|
|
BOOST_CONTRACT_ASSERT(get() == *old_get - 10);
|
|
})
|
|
;
|
|
|
|
set(get() - 10);
|
|
}
|
|
|
|
/* ... */
|
|
//]
|
|
|
|
virtual int get(boost::contract::virtual_* v = 0) const {
|
|
int result;
|
|
boost::contract::check c = boost::contract::public_function<
|
|
override_get>(v, result, &counter10::get, this);
|
|
|
|
return result = counter::get();
|
|
}
|
|
BOOST_CONTRACT_OVERRIDE(get)
|
|
|
|
// Should contract default constructor and destructor too.
|
|
|
|
void invariant() const {
|
|
BOOST_CONTRACT_ASSERT(get() % 10 == 0);
|
|
}
|
|
};
|
|
|
|
int main() {
|
|
counter cnt;
|
|
assert(cnt.get() == 0);
|
|
cnt.dec();
|
|
assert(cnt.get() == -1);
|
|
|
|
counter10 cnt10;
|
|
counter& b = cnt10; // Polymorphic calls.
|
|
assert(b.get() == 0);
|
|
b.dec();
|
|
assert(b.get() == -10);
|
|
|
|
return 0;
|
|
}
|
|
|