From 7b277e8b464b28c76a751fbb811c419d79a3f715 Mon Sep 17 00:00:00 2001
From: Tim Shen <timshen@google.com>
Date: Tue, 15 Nov 2016 17:26:59 +0000
Subject: [PATCH] variant: Remove variant<T&>...
* include/std/variant: Remove variant<T&>, variant<void>, variant<> support
to rebase on the post-Issaquah design.
* testsuite/20_util/variant/compile.cc: Likewise.
From-SVN: r242437
---
libstdc++-v3/ChangeLog | 10 +-
libstdc++-v3/include/std/variant | 77 ++-------
.../testsuite/20_util/variant/compile.cc | 149 +-----------------
3 files changed, 28 insertions(+), 208 deletions(-)
diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 54bf54d00233..cc72f15c4b83 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,9 @@
+2016-11-15 Tim Shen <timshen@google.com>
+
+ * include/std/variant: Remove variant<T&>, variant<void>, variant<> support
+ to rebase on the post-Issaquah design.
+ * testsuite/20_util/variant/compile.cc: Likewise.
+
2016-11-15 Matthias Klose <doko@ubuntu.com>
* configure: Regenerate.
@@ -341,9 +347,9 @@
2016-11-09 Tim Shen <timshen@google.com>
- * libstdc++-v3/include/bits/regex.h (regex_iterator::regex_iterator()):
+ * include/bits/regex.h (regex_iterator::regex_iterator()):
Define end() as _M_pregex == nullptr.
- * libstdc++-v3/include/bits/regex.tcc (regex_iterator::operator==(),
+ * include/bits/regex.tcc (regex_iterator::operator==(),
regex_iterator::operator++()): Fix operator==() and operator++() to
look at null-ness of _M_pregex on both sides.
* testsuite/28_regex/regression.cc: New testcase.
diff --git a/libstdc++-v3/include/std/variant b/libstdc++-v3/include/std/variant
index 6f3f67c57809..7d9357537289 100644
--- a/libstdc++-v3/include/std/variant
+++ b/libstdc++-v3/include/std/variant
@@ -137,41 +137,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
struct __reserved_type_map_impl<const volatile _From, _To>
{ using type = add_cv_t<__reserved_type_map<_From, _To>>; };
- // Stores a reference alternative as a... well, reference.
- template<typename _Reference>
- struct _Reference_storage
- {
- static_assert(is_reference_v<_Reference>,
- "BUG: _Reference should be a reference");
-
- _Reference_storage(_Reference __ref) noexcept : _M_storage(__ref) { }
-
- operator _Reference() noexcept
- { return static_cast<_Reference>(_M_storage); }
-
- _Reference _M_storage;
- };
-
- // Stores a void alternative, because it is not a regular type.
- template<typename _Void>
- struct _Void_storage { };
-
- // Map from the alternative type to a non-qualified storage type.
- template<typename _Alternative, typename = void>
- struct __storage_type
- { using type = _Alternative; };
-
- template<typename _Alternative>
- struct __storage_type<_Alternative,
- enable_if_t<is_reference_v<_Alternative>>>
- { using type = _Reference_storage<_Alternative>; };
-
+ // This abstraction might be useful for future features,
+ // e.g. boost::recursive_wrapper.
template<typename _Alternative>
- struct __storage_type<_Alternative, enable_if_t<is_void_v<_Alternative>>>
- { using type = _Void_storage<_Alternative>; };
-
- template<typename _Type>
- using __storage = typename __storage_type<_Type>::type;
+ using __storage = _Alternative;
template<typename _Type, bool __is_literal = std::is_literal_type_v<_Type>>
struct _Uninitialized;
@@ -202,37 +171,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_M_storage;
};
- // Reverse mapping of __storage_type.
- template<typename _Storage_type>
- struct __alternative_type
- {
- static_assert(!is_reference_v<_Storage_type>,
- "BUG: _Storage_type should not be reference");
- using type = _Storage_type;
- };
-
- template<typename _Reference>
- struct __alternative_type<_Reference_storage<_Reference>>
- { using type = _Reference; };
-
- template<typename _Void>
- struct __alternative_type<_Void_storage<_Void>>
- { using type = _Void; };
-
// Given a qualified storage type, return the desired reference.
- // The qualified storage type is supposed to carry the variant object's
- // qualifications and reference information, and the designated alternative's
- // storage type.
- // Returns the qualification-collapsed alternative references.
- //
- // For example, __get_alternative<_Reference_storage<int&&>&> returns int&.
+ // For example, variant<int>&& stores the int as __storage<int>, and
+ // _Qualified_storage will be __storage<int>&&.
template<typename _Qualified_storage>
decltype(auto)
__get_alternative(void* __ptr)
{
using _Storage = decay_t<_Qualified_storage>;
- using _Alternative = typename __alternative_type<_Storage>::type;
- return __reserved_type_map<_Qualified_storage, _Alternative>(
+ return __reserved_type_map<_Qualified_storage, _Storage>(
*static_cast<_Storage*>(__ptr));
}
@@ -970,6 +917,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
variant<_Types...>>
{
private:
+ static_assert(sizeof...(_Types) > 0,
+ "variant must have at least one alternative");
+ static_assert(!(std::is_reference_v<_Types> || ...),
+ "variant must have no reference alternative");
+ static_assert(!(std::is_void_v<_Types> || ...),
+ "variant must have no void alternative");
+
using _Base = __detail::__variant::_Variant_base<_Types...>;
using _Default_ctor_enabler =
_Enable_default_constructor<
@@ -1265,11 +1219,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
__get_storage(_Vp&& __v);
};
- // To honor algebraic data type, variant<> should be a bottom type, which
- // is 0 (as opposed to a void type, which is 1). Use incomplete type to model
- // bottom type.
- template<> class variant<>;
-
template<size_t _Np, typename... _Types>
variant_alternative_t<_Np, variant<_Types...>>&
get(variant<_Types...>& __v)
diff --git a/libstdc++-v3/testsuite/20_util/variant/compile.cc b/libstdc++-v3/testsuite/20_util/variant/compile.cc
index 08de71e7ccea..2470bcc7f9ea 100644
--- a/libstdc++-v3/testsuite/20_util/variant/compile.cc
+++ b/libstdc++-v3/testsuite/20_util/variant/compile.cc
@@ -55,7 +55,6 @@ void default_ctor()
{
static_assert(is_default_constructible_v<variant<int, string>>, "");
static_assert(is_default_constructible_v<variant<string, string>>, "");
- static_assert(!is_default_constructible_v<variant<>>, "");
static_assert(!is_default_constructible_v<variant<AllDeleted, string>>, "");
static_assert(is_default_constructible_v<variant<string, AllDeleted>>, "");
@@ -123,14 +122,6 @@ void uses_alloc_ctors()
std::allocator<char> alloc;
variant<int> a(allocator_arg, alloc);
static_assert(!is_constructible_v<variant<AllDeleted>, allocator_arg_t, std::allocator<char>>, "");
- {
- variant<int> b(allocator_arg, alloc, a);
- static_assert(!is_constructible_v<variant<void>, allocator_arg_t, std::allocator<char>, const variant<void>&>, "");
- }
- {
- variant<int> b(allocator_arg, alloc, std::move(a));
- static_assert(!is_constructible_v<variant<void>, allocator_arg_t, std::allocator<char>, variant<void>&&>, "");
- }
{
variant<string, int> b(allocator_arg, alloc, "a");
static_assert(!is_constructible_v<variant<string, string>, allocator_arg_t, std::allocator<char>, const char*>, "");
@@ -169,12 +160,6 @@ void copy_assign()
variant<DefaultNoexcept> a;
static_assert(!noexcept(a = a), "");
}
-
- {
- float f1 = 1.0f, f2 = 2.0f;
- std::variant<float&> v1(f1);
- v1 = f2;
- }
}
void move_assign()
@@ -203,103 +188,13 @@ void arbitrary_assign()
void test_get()
{
- {
- static_assert(is_same<decltype(get<0>(variant<int, string>())), int&&>::value, "");
- static_assert(is_same<decltype(get<1>(variant<int, string>())), string&&>::value, "");
- static_assert(is_same<decltype(get<1>(variant<int, string&>())), string&>::value, "");
- static_assert(is_same<decltype(get<1>(variant<int, string&&>())), string&&>::value, "");
- static_assert(is_same<decltype(get<1>(variant<int, const string>())), const string&&>::value, "");
- static_assert(is_same<decltype(get<1>(variant<int, const string&>())), const string&>::value, "");
- static_assert(is_same<decltype(get<1>(variant<int, const string&&>())), const string&&>::value, "");
-
- static_assert(is_same<decltype(get<int>(variant<int, string>())), int&&>::value, "");
- static_assert(is_same<decltype(get<string>(variant<int, string>())), string&&>::value, "");
- static_assert(is_same<decltype(get<string&>(variant<int, string&>())), string&>::value, "");
- static_assert(is_same<decltype(get<string&&>(variant<int, string&&>())), string&&>::value, "");
- static_assert(is_same<decltype(get<const string>(variant<int, const string>())), const string&&>::value, "");
- static_assert(is_same<decltype(get<const string&>(variant<int, const string&>())), const string&>::value, "");
- static_assert(is_same<decltype(get<const string&&>(variant<int, const string&&>())), const string&&>::value, "");
- }
- {
- variant<int, string> a;
- variant<int, string&> b;
- variant<int, string&&> c;
- variant<int, const string> d;
- variant<int, const string&> e;
- variant<int, const string&&> f;
-
- static_assert(is_same<decltype(get<0>(a)), int&>::value, "");
- static_assert(is_same<decltype(get<1>(a)), string&>::value, "");
- static_assert(is_same<decltype(get<1>(b)), string&>::value, "");
- static_assert(is_same<decltype(get<1>(c)), string&>::value, "");
- static_assert(is_same<decltype(get<1>(e)), const string&>::value, "");
- static_assert(is_same<decltype(get<1>(e)), const string&>::value, "");
- static_assert(is_same<decltype(get<1>(f)), const string&>::value, "");
-
- static_assert(is_same<decltype(get<int>(a)), int&>::value, "");
- static_assert(is_same<decltype(get<string>(a)), string&>::value, "");
- static_assert(is_same<decltype(get<string&>(b)), string&>::value, "");
- static_assert(is_same<decltype(get<string&&>(c)), string&>::value, "");
- static_assert(is_same<decltype(get<const string>(e)), const string&>::value, "");
- static_assert(is_same<decltype(get<const string&>(e)), const string&>::value, "");
- static_assert(is_same<decltype(get<const string&&>(f)), const string&>::value, "");
-
- static_assert(is_same<decltype(get_if<0>(&a)), int*>::value, "");
- static_assert(is_same<decltype(get_if<1>(&a)), string*>::value, "");
- static_assert(is_same<decltype(get_if<1>(&b)), string*>::value, "");
- static_assert(is_same<decltype(get_if<1>(&c)), string*>::value, "");
- static_assert(is_same<decltype(get_if<1>(&e)), const string*>::value, "");
- static_assert(is_same<decltype(get_if<1>(&e)), const string*>::value, "");
- static_assert(is_same<decltype(get_if<1>(&f)), const string*>::value, "");
-
- static_assert(is_same<decltype(get_if<int>(&a)), int*>::value, "");
- static_assert(is_same<decltype(get_if<string>(&a)), string*>::value, "");
- static_assert(is_same<decltype(get_if<string&>(&b)), string*>::value, "");
- static_assert(is_same<decltype(get_if<string&&>(&c)), string*>::value, "");
- static_assert(is_same<decltype(get_if<const string>(&e)), const string*>::value, "");
- static_assert(is_same<decltype(get_if<const string&>(&e)), const string*>::value, "");
- static_assert(is_same<decltype(get_if<const string&&>(&f)), const string*>::value, "");
- }
- {
- const variant<int, string> a;
- const variant<int, string&> b;
- const variant<int, string&&> c;
- const variant<int, const string> d;
- const variant<int, const string&> e;
- const variant<int, const string&&> f;
-
- static_assert(is_same<decltype(get<0>(a)), const int&>::value, "");
- static_assert(is_same<decltype(get<1>(a)), const string&>::value, "");
- static_assert(is_same<decltype(get<1>(b)), string&>::value, "");
- static_assert(is_same<decltype(get<1>(c)), string&>::value, "");
- static_assert(is_same<decltype(get<1>(d)), const string&>::value, "");
- static_assert(is_same<decltype(get<1>(e)), const string&>::value, "");
- static_assert(is_same<decltype(get<1>(f)), const string&>::value, "");
-
- static_assert(is_same<decltype(get<int>(a)), const int&>::value, "");
- static_assert(is_same<decltype(get<string>(a)), const string&>::value, "");
- static_assert(is_same<decltype(get<string&>(b)), string&>::value, "");
- static_assert(is_same<decltype(get<string&&>(c)), string&>::value, "");
- static_assert(is_same<decltype(get<const string>(d)), const string&>::value, "");
- static_assert(is_same<decltype(get<const string&>(e)), const string&>::value, "");
- static_assert(is_same<decltype(get<const string&&>(f)), const string&>::value, "");
-
- static_assert(is_same<decltype(get_if<0>(&a)), const int*>::value, "");
- static_assert(is_same<decltype(get_if<1>(&a)), const string*>::value, "");
- static_assert(is_same<decltype(get_if<1>(&b)), string*>::value, "");
- static_assert(is_same<decltype(get_if<1>(&c)), string*>::value, "");
- static_assert(is_same<decltype(get_if<1>(&d)), const string*>::value, "");
- static_assert(is_same<decltype(get_if<1>(&e)), const string*>::value, "");
- static_assert(is_same<decltype(get_if<1>(&f)), const string*>::value, "");
-
- static_assert(is_same<decltype(get_if<int>(&a)), const int*>::value, "");
- static_assert(is_same<decltype(get_if<string>(&a)), const string*>::value, "");
- static_assert(is_same<decltype(get_if<string&>(&b)), string*>::value, "");
- static_assert(is_same<decltype(get_if<string&&>(&c)), string*>::value, "");
- static_assert(is_same<decltype(get_if<const string>(&d)), const string*>::value, "");
- static_assert(is_same<decltype(get_if<const string&>(&e)), const string*>::value, "");
- static_assert(is_same<decltype(get_if<const string&&>(&f)), const string*>::value, "");
- }
+ static_assert(is_same<decltype(get<0>(variant<int, string>())), int&&>::value, "");
+ static_assert(is_same<decltype(get<1>(variant<int, string>())), string&&>::value, "");
+ static_assert(is_same<decltype(get<1>(variant<int, const string>())), const string&&>::value, "");
+
+ static_assert(is_same<decltype(get<int>(variant<int, string>())), int&&>::value, "");
+ static_assert(is_same<decltype(get<string>(variant<int, string>())), string&&>::value, "");
+ static_assert(is_same<decltype(get<const string>(variant<int, const string>())), const string&&>::value, "");
}
void test_relational()
@@ -344,16 +239,6 @@ void test_visit()
void operator()(monostate) const {}
void operator()(const int&) const {}
};
- variant<monostate, int&, const int&, int&&, const int&&> a;
- const variant<monostate, int&, const int&, int&&, const int&&> b;
- Visitor v;
- const CVisitor u;
- static_assert(is_same<void, decltype(visit(Visitor(), a))>::value, "");
- static_assert(is_same<void, decltype(visit(Visitor(), b))>::value, "");
- static_assert(is_same<void, decltype(visit(v, a))>::value, "");
- static_assert(is_same<void, decltype(visit(v, b))>::value, "");
- static_assert(is_same<void, decltype(visit(u, a))>::value, "");
- static_assert(is_same<void, decltype(visit(u, b))>::value, "");
}
{
struct Visitor
@@ -397,19 +282,6 @@ void test_constexpr()
}
}
-void test_void()
-{
- static_assert(is_same<int&&, decltype(get<int>(variant<int, void>()))>::value, "");
- static_assert(!is_default_constructible_v<variant<void, int>>, "");
- static_assert(!is_copy_constructible_v<variant<int, void>>, "");
- static_assert(!is_move_constructible_v<variant<int, void>>, "");
- static_assert(!is_copy_assignable_v<variant<int, void>>, "");
- static_assert(!is_move_assignable_v<variant<int, void>>, "");
- variant<int, void, string> v;
- v = 3;
- v = "asdf";
-}
-
void test_pr77641()
{
struct X {
@@ -457,11 +329,4 @@ void test_adl()
variant<X> v7{allocator_arg, a, in_place_index<0>, il, x};
variant<X> v8{allocator_arg, a, in_place_type<X>, il, x};
variant<X> v9{allocator_arg, a, in_place_type<X>, 1};
-
- std::variant<X&> vr0(x);
- vr0 = x;
- variant<X&> vr1{in_place_index<0>, x};
- variant<X&> vr2{in_place_type<X&>, x};
- variant<X&> vr3{allocator_arg, a, in_place_index<0>, x};
- variant<X&> vr4{allocator_arg, a, in_place_type<X&>, x};
}
--
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