[PATCH] libstdc++: Implement new predicate concepts from P1716R3
Jonathan Wakely
jwakely@redhat.com
Thu Nov 14 16:53:00 GMT 2019
* include/bits/iterator_concepts.h (__iter_concept_impl): Add
comments.
(indirect_relation): Rename to indirect_binary_predicate and adjust
definition as per P1716R3.
(indirect_equivalence_relation): Define.
(indirectly_comparable): Adjust definition.
* include/std/concepts (equivalence_relation): Define.
* testsuite/std/concepts/concepts.callable/relation.cc: Add tests for
equivalence_relation.
Tested powerpc64le-linux, committed to trunk.
-------------- next part --------------
commit 01e0b14116ce56d4327362686334c37272faac43
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Wed Nov 13 22:26:06 2019 +0000
libstdc++: Implement new predicate concepts from P1716R3
* include/bits/iterator_concepts.h (__iter_concept_impl): Add
comments.
(indirect_relation): Rename to indirect_binary_predicate and adjust
definition as per P1716R3.
(indirect_equivalence_relation): Define.
(indirectly_comparable): Adjust definition.
* include/std/concepts (equivalence_relation): Define.
* testsuite/std/concepts/concepts.callable/relation.cc: Add tests for
equivalence_relation.
diff --git a/libstdc++-v3/include/bits/iterator_concepts.h b/libstdc++-v3/include/bits/iterator_concepts.h
index 7cc058eb8c9..90a8bc8071f 100644
--- a/libstdc++-v3/include/bits/iterator_concepts.h
+++ b/libstdc++-v3/include/bits/iterator_concepts.h
@@ -420,20 +420,22 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
namespace __detail
{
template<typename _Iter>
- struct __iter_concept_impl
- { };
+ struct __iter_concept_impl;
+ // ITER_CONCEPT(I) is ITER_TRAITS(I)::iterator_concept if that is valid.
template<typename _Iter>
requires requires { typename __iter_traits<_Iter>::iterator_concept; }
struct __iter_concept_impl<_Iter>
{ using type = typename __iter_traits<_Iter>::iterator_concept; };
+ // Otherwise, ITER_TRAITS(I)::iterator_category if that is valid.
template<typename _Iter>
requires (!requires { typename __iter_traits<_Iter>::iterator_concept; }
&& requires { typename __iter_traits<_Iter>::iterator_category; })
struct __iter_concept_impl<_Iter>
{ using type = typename __iter_traits<_Iter>::iterator_category; };
+ // Otherwise, random_access_tag if iterator_traits<I> is not specialized.
template<typename _Iter>
requires (!requires { typename __iter_traits<_Iter>::iterator_concept; }
&& !requires { typename __iter_traits<_Iter>::iterator_category; }
@@ -441,7 +443,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
struct __iter_concept_impl<_Iter>
{ using type = random_access_iterator_tag; };
- // ITER_TRAITS
+ // Otherwise, there is no ITER_CONCEPT(I) type.
+ template<typename _Iter>
+ struct __iter_concept_impl
+ { };
+
+ // ITER_CONCEPT
template<typename _Iter>
using __iter_concept = typename __iter_concept_impl<_Iter>::type;
} // namespace __detail
@@ -615,15 +622,26 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
&& predicate<_Fn&, iter_reference_t<_Iter>>
&& predicate<_Fn&, iter_common_reference_t<_Iter>>;
- template<typename _Fn, typename _I1, typename _I2 = _I1>
- concept indirect_relation = readable<_I1> && readable<_I2>
+ template<typename _Fn, typename _I1, typename _I2>
+ concept indirect_binary_predicate = readable<_I1> && readable<_I2>
&& copy_constructible<_Fn>
- && relation<_Fn&, iter_value_t<_I1>&, iter_value_t<_I2>&>
- && relation<_Fn&, iter_value_t<_I1>&, iter_reference_t<_I2>>
- && relation<_Fn&, iter_reference_t<_I1>, iter_value_t<_I2>&>
- && relation<_Fn&, iter_reference_t<_I1>, iter_reference_t<_I2>>
- && relation<_Fn&, iter_common_reference_t<_I1>,
- iter_common_reference_t<_I2>>;
+ && predicate<_Fn&, iter_value_t<_I1>&, iter_value_t<_I2>&>
+ && predicate<_Fn&, iter_value_t<_I1>&, iter_reference_t<_I2>>
+ && predicate<_Fn&, iter_reference_t<_I1>, iter_value_t<_I2>&>
+ && predicate<_Fn&, iter_reference_t<_I1>, iter_reference_t<_I2>>
+ && predicate<_Fn&, iter_common_reference_t<_I1>,
+ iter_common_reference_t<_I2>>;
+
+ template<typename _Fn, typename _I1, typename _I2 = _I1>
+ concept indirect_equivalence_relation = readable<_I1> && readable<_I2>
+ && copy_constructible<_Fn>
+ && equivalence_relation<_Fn&, iter_value_t<_I1>&, iter_value_t<_I2>&>
+ && equivalence_relation<_Fn&, iter_value_t<_I1>&, iter_reference_t<_I2>>
+ && equivalence_relation<_Fn&, iter_reference_t<_I1>, iter_value_t<_I2>&>
+ && equivalence_relation<_Fn&, iter_reference_t<_I1>,
+ iter_reference_t<_I2>>
+ && equivalence_relation<_Fn&, iter_common_reference_t<_I1>,
+ iter_common_reference_t<_I2>>;
template<typename _Fn, typename _I1, typename _I2 = _I1>
concept indirect_strict_weak_order = readable<_I1> && readable<_I2>
@@ -767,7 +785,8 @@ namespace ranges
template<typename _I1, typename _I2, typename _Rel, typename _P1 = identity,
typename _P2 = identity>
concept indirectly_comparable
- = indirect_relation<_Rel, projected<_I1, _P1>, projected<_I2, _P2>>;
+ = indirect_binary_predicate<_Rel, projected<_I1, _P1>,
+ projected<_I2, _P2>>;
/// [alg.req.permutable], concept `permutable`
template<typename _Iter>
diff --git a/libstdc++-v3/include/std/concepts b/libstdc++-v3/include/std/concepts
index c4acfd2e212..e6d405a1bee 100644
--- a/libstdc++-v3/include/std/concepts
+++ b/libstdc++-v3/include/std/concepts
@@ -334,26 +334,30 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
// [concepts.callable], callable concepts
- // [concept.invocable], concept invocable
+ /// [concept.invocable], concept invocable
template<typename _Fn, typename... _Args>
concept invocable = is_invocable_v<_Fn, _Args...>;
- // [concept.regularinvocable], concept regular_invocable
+ /// [concept.regularinvocable], concept regular_invocable
template<typename _Fn, typename... _Args>
concept regular_invocable = invocable<_Fn, _Args...>;
- // [concept.predicate], concept predicate
+ /// [concept.predicate], concept predicate
template<typename _Fn, typename... _Args>
concept predicate = regular_invocable<_Fn, _Args...>
&& boolean<invoke_result_t<_Fn, _Args...>>;
- // [concept.relation], concept relation
+ /// [concept.relation], concept relation
template<typename _Rel, typename _Tp, typename _Up>
concept relation
= predicate<_Rel, _Tp, _Tp> && predicate<_Rel, _Up, _Up>
&& predicate<_Rel, _Tp, _Up> && predicate<_Rel, _Up, _Tp>;
- // [concept.strictweakorder], concept strict_weak_order
+ /// [concept.equiv], concept equivalence_relation
+ template<typename _Rel, typename _Tp, typename _Up>
+ concept equivalence_relation = relation<_Rel, _Tp, _Up>;
+
+ /// [concept.strictweakorder], concept strict_weak_order
template<typename _Rel, typename _Tp, typename _Up>
concept strict_weak_order = relation<_Rel, _Tp, _Up>;
diff --git a/libstdc++-v3/testsuite/std/concepts/concepts.callable/relation.cc b/libstdc++-v3/testsuite/std/concepts/concepts.callable/relation.cc
index 783c3ab9c4a..73ff54bbb6d 100644
--- a/libstdc++-v3/testsuite/std/concepts/concepts.callable/relation.cc
+++ b/libstdc++-v3/testsuite/std/concepts/concepts.callable/relation.cc
@@ -46,3 +46,8 @@ struct F
static_assert( ! std::relation<F, long, long> );
static_assert( std::relation<F&, int, int> );
static_assert( std::relation<const F&, const int, const int> );
+
+// [concept.equiv]
+static_assert( std::equivalence_relation<bool(*)(int, int), short, long> );
+static_assert( ! std::equivalence_relation<F, long, long> );
+static_assert( std::equivalence_relation<const F&, const int, const int> );
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