xref: /llvm-project/clang/test/Modules/pr62796.cppm (revision da00c60dae0040185dc45039c4397f6e746548e9)
1// RUN: rm -rf %t
2// RUN: mkdir -p %t
3// RUN: split-file %s %t
4//
5// RUN: %clang_cc1 -std=c++20 -emit-module-interface %t/Cache.cppm -o %t/Cache.pcm
6// RUN: %clang_cc1 -std=c++20 %t/Use.cpp -fmodule-file=Fibonacci.Cache=%t/Cache.pcm \
7// RUN:     -fsyntax-only -verify
8
9// RUN: %clang_cc1 -std=c++20 -emit-reduced-module-interface %t/Cache.cppm -o %t/Cache.pcm
10// RUN: %clang_cc1 -std=c++20 %t/Use.cpp -fmodule-file=Fibonacci.Cache=%t/Cache.pcm \
11// RUN:     -fsyntax-only -verify
12
13//--- Cache.cppm
14export module Fibonacci.Cache;
15
16export namespace Fibonacci
17{
18	constexpr unsigned long Recursive(unsigned long n)
19	{
20		if (n == 0)
21			return 0;
22		if (n == 1)
23			return 1;
24		return Recursive(n - 2) + Recursive(n - 1);
25	}
26
27	template<unsigned long N>
28	struct Number{};
29
30	struct DefaultStrategy
31	{
32		constexpr unsigned long operator()(unsigned long n, auto... other) const
33		{
34			return (n + ... + other);
35		}
36	};
37
38    constexpr unsigned long Compute(Number<10ul>, auto strategy)
39	{
40		return strategy(Recursive(10ul));
41	}
42
43	template<unsigned long N, typename Strategy = DefaultStrategy>
44	constexpr unsigned long Cache = Compute(Number<N>{}, Strategy{});
45
46    template constexpr unsigned long Cache<10ul>;
47}
48
49//--- Use.cpp
50// expected-no-diagnostics
51import Fibonacci.Cache;
52
53constexpr bool value = Fibonacci::Cache<10ul> == 55;
54
55static_assert(value == true, "");
56