Tested on x86_64-pc-linux-gnu, does this look OK for trunk? libstdc++-v3/ChangeLog:
* testsuite/20_util/logical_traits/requirements/short_circuit.cc: New test. --- .../requirements/short_circuit.cc | 32 +++++++++++++++++++ 1 file changed, 32 insertions(+) create mode 100644 libstdc++-v3/testsuite/20_util/logical_traits/requirements/short_circuit.cc 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..b6a8091cdb0 --- /dev/null +++ b/libstdc++-v3/testsuite/20_util/logical_traits/requirements/short_circuit.cc @@ -0,0 +1,32 @@ +// { 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::false_type>); + +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>); +static_assert(!std::conjunction_v<std::true_type, std::false_type>); + +// [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::true_type>); + +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>); +static_assert(std::disjunction_v<std::false_type, std::true_type>); -- 2.37.2.490.g6c8e4ee870