66 lines
1.3 KiB
C++
66 lines
1.3 KiB
C++
|
|
// Copyright 2005 Daniel James.
|
|
// Copyright 2022 Peter Dimov.
|
|
// Distributed under the Boost Software License, Version 1.0.
|
|
// https://www.boost.org/LICENSE_1_0.txt
|
|
|
|
// Force use of assert.
|
|
#if defined(NDEBUG)
|
|
#undef NDEBUG
|
|
#endif
|
|
|
|
#include <boost/container_hash/hash.hpp>
|
|
#include <boost/describe/class.hpp>
|
|
#include <boost/describe/operators.hpp>
|
|
#include <cassert>
|
|
|
|
// This example illustrates how to use Boost.Describe to obtain
|
|
// automatic boost::hash support. For full details see the hash
|
|
// tutorial.
|
|
|
|
#if defined(BOOST_DESCRIBE_CXX14)
|
|
|
|
class point
|
|
{
|
|
int x;
|
|
int y;
|
|
|
|
BOOST_DESCRIBE_CLASS(point, (), (), (), (x, y))
|
|
|
|
public:
|
|
|
|
point() : x(0), y(0) {}
|
|
point(int x, int y) : x(x), y(y) {}
|
|
};
|
|
|
|
using boost::describe::operators::operator==;
|
|
using boost::describe::operators::operator!=;
|
|
|
|
int main()
|
|
{
|
|
boost::hash<point> point_hasher;
|
|
|
|
point p1(0, 0);
|
|
point p2(1, 2);
|
|
point p3(4, 1);
|
|
point p4 = p1;
|
|
|
|
assert(point_hasher(p1) == point_hasher(p4));
|
|
|
|
// These tests could legally fail, but if they did it'd be a pretty bad
|
|
// hash function.
|
|
assert(point_hasher(p1) != point_hasher(p2));
|
|
assert(point_hasher(p1) != point_hasher(p3));
|
|
}
|
|
|
|
#else
|
|
|
|
#include <cstdio>
|
|
|
|
int main()
|
|
{
|
|
std::puts( "This example requires C++14." );
|
|
}
|
|
|
|
#endif
|