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// Copyright 2024 Peter Dimov
// Distributed under the Boost Software License, Version 1.0.
// https://www.boost.org/LICENSE_1_0.txt
#include <boost/uuid/time_generator_v7.hpp>
#include <boost/core/lightweight_test.hpp>
#include <chrono>
#include <set>
using namespace boost::uuids;
uuid generate_and_test( time_generator_v7& gen )
{
auto sys_before = std::chrono::time_point_cast<std::chrono::milliseconds>( std::chrono::system_clock::now() );
uuid u = gen();
BOOST_TEST_EQ( u.variant(), uuid::variant_rfc_4122 );
BOOST_TEST_EQ( u.version(), uuid::version_time_based_v7 );
// The below is an unsupported way to obtain the
// microsecond part of our UUIDv7 timestamps.
//
// It's not guaranteed by the specification and may
// break in future releases.
std::uint64_t time_in_us = u.timestamp_v6() & 0xFFF; // v6 time_low field
// time_in_us occasionally exceeds 999 when the clock
// resolution is sufficiently low (MinGW)
BOOST_TEST_LT( time_in_us, 1024 );
auto sys_after = std::chrono::time_point_cast<std::chrono::milliseconds>( std::chrono::system_clock::now() );
auto sys_time_point = u.time_point_v7();
BOOST_TEST( sys_before <= sys_time_point );
BOOST_TEST( sys_time_point <= sys_after );
return u;
}
int main()
{
int const N = 1024;
{
std::set<uuid> set;
time_generator_v7 gen;
uuid u1 = generate_and_test( gen );
set.insert( u1 );
for( int i = 0; i < N; ++i )
{
uuid u2 = generate_and_test( gen );
set.insert( u2 );
}
BOOST_TEST_EQ( set.size(), N + 1 );
}
return boost::report_errors();
}
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