Files
clang-p2996/libcxx/test/std/experimental/reflection/p2996-ex-compile-time-ticket-counter.pass.cpp
2025-06-24 11:01:59 -04:00

56 lines
1.4 KiB
C++

//===----------------------------------------------------------------------===//
//
// Copyright 2024 Bloomberg Finance L.P.
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++03 || c++11 || c++14 || c++17 || c++20
// ADDITIONAL_COMPILE_FLAGS: -freflection
// <experimental/reflection>
//
// [reflection]
//
// RUN: %{build}
// RUN: %{exec} %t.exe > %t.stdout
#include <meta>
#include <print>
template<int N> struct Helper;
struct TU_Ticket {
static consteval int latest() {
int k = 0;
while (is_complete_type(substitute(^^Helper,
{ std::meta::reflect_constant(k) })))
++k;
return k;
}
static consteval void increment() {
define_aggregate(substitute(^^Helper,
{ std::meta::reflect_constant(latest())}),
{});
}
};
constexpr int x = TU_Ticket::latest(); // x initialized to 0.
consteval { TU_Ticket::increment(); }
constexpr int y = TU_Ticket::latest(); // y initialized to 1.
consteval { TU_Ticket::increment(); }
constexpr int z = TU_Ticket::latest(); // z initialized to 2.
int main() {
// RUN: grep "0, 1, 2" %t.stdout
std::println("{}, {}, {}", x, y, z);
}