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From: Patrick Palka <ppalka@gcc.gnu.org>
To: gcc-cvs@gcc.gnu.org, libstdc++-cvs@gcc.gnu.org
Subject: [gcc r13-2313] libstdc++: Add test for std::con/disjunction's short circuiting
Date: Wed, 31 Aug 2022 14:05:26 +0000 (GMT)	[thread overview]
Message-ID: <20220831140526.26628383FB9B@sourceware.org> (raw)

https://gcc.gnu.org/g:caaf9e66c498d9d6dc8be665d820ab45afa406ae

commit r13-2313-gcaaf9e66c498d9d6dc8be665d820ab45afa406ae
Author: Patrick Palka <ppalka@redhat.com>
Date:   Wed Aug 31 10:04:54 2022 -0400

    libstdc++: Add test for std::con/disjunction's short circuiting
    
    libstdc++-v3/ChangeLog:
    
            * testsuite/20_util/logical_traits/requirements/short_circuit.cc: New test.

Diff:
---
 .../logical_traits/requirements/short_circuit.cc   | 26 ++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/libstdc++-v3/testsuite/20_util/logical_traits/requirements/short_circuit.cc b/libstdc++-v3/testsuite/20_util/logical_traits/requirements/short_circuit.cc
new file mode 100644
index 00000000000..86996b27fa5
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/logical_traits/requirements/short_circuit.cc
@@ -0,0 +1,26 @@
+// { dg-do compile { target c++17 } }
+
+#include <type_traits>
+
+template<class T> struct A { using type = typename T::type; };
+using invalid = A<void>;
+
+// [meta.logical]/3: For a specialization conjunction<B_1, ..., B_n>, if
+// there is a template type argument B_i for which bool(B_i::value) is false,
+// then instantiating conjunction<B_1, ..., B_n>::value does not require the
+// instantiation of B_j::value for j > i.
+
+static_assert(!std::conjunction_v<std::false_type, invalid>);
+static_assert(!std::conjunction_v<std::false_type, invalid, invalid>);
+static_assert(!std::conjunction_v<std::true_type, std::false_type, invalid>);
+static_assert(!std::conjunction_v<std::true_type, std::false_type, invalid, invalid>);
+
+// [meta.logical]/8: For a specialization disjunction<B_1, ..., B_n>, if
+// there is a template type argument B_i for which bool(B_i::value) is true,
+// then instantiating disjunction<B_1, ..., B_n>::value does not require the
+// instantiation of B_j::value for j > i.
+
+static_assert(std::disjunction_v<std::true_type, invalid>);
+static_assert(std::disjunction_v<std::true_type, invalid, invalid>);
+static_assert(std::disjunction_v<std::false_type, std::true_type, invalid>);
+static_assert(std::disjunction_v<std::false_type, std::true_type, invalid, invalid>);

                 reply	other threads:[~2022-08-31 14:05 UTC|newest]

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