gcc/libstdc++-v3/testsuite/20_util/variant/compile.cc
2021-01-04 10:26:59 +01:00

620 lines
21 KiB
C++

// { dg-options "-std=gnu++17" }
// { dg-do compile { target c++17 } }
// Copyright (C) 2016-2021 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING3. If not see
// <http://www.gnu.org/licenses/>.
#include <variant>
#include <string>
#include <vector>
using namespace std;
struct AllDeleted
{
AllDeleted() = delete;
AllDeleted(const AllDeleted&) = delete;
AllDeleted(AllDeleted&&) = delete;
AllDeleted& operator=(const AllDeleted&) = delete;
AllDeleted& operator=(AllDeleted&&) = delete;
};
struct Empty
{
Empty() { };
Empty(const Empty&) { };
Empty(Empty&&) { };
Empty& operator=(const Empty&) { return *this; };
Empty& operator=(Empty&&) { return *this; };
};
struct DefaultNoexcept
{
DefaultNoexcept() noexcept = default;
DefaultNoexcept(const DefaultNoexcept&) noexcept = default;
DefaultNoexcept(DefaultNoexcept&&) noexcept = default;
DefaultNoexcept& operator=(const DefaultNoexcept&) noexcept = default;
DefaultNoexcept& operator=(DefaultNoexcept&&) noexcept = default;
};
struct MoveCtorOnly
{
MoveCtorOnly() noexcept = delete;
MoveCtorOnly(const MoveCtorOnly&) noexcept = delete;
MoveCtorOnly(MoveCtorOnly&&) noexcept { }
MoveCtorOnly& operator=(const MoveCtorOnly&) noexcept = delete;
MoveCtorOnly& operator=(MoveCtorOnly&&) noexcept = delete;
};
struct MoveCtorAndSwapOnly : MoveCtorOnly { };
void swap(MoveCtorAndSwapOnly&, MoveCtorAndSwapOnly&) { }
struct DeletedMoves
{
DeletedMoves() = default;
DeletedMoves(const DeletedMoves&) = default;
DeletedMoves(DeletedMoves&&) = delete;
DeletedMoves& operator=(const DeletedMoves&) = default;
DeletedMoves& operator=(DeletedMoves&&) = delete;
};
struct nonliteral
{
nonliteral() { }
bool operator<(const nonliteral&) const;
bool operator<=(const nonliteral&) const;
bool operator==(const nonliteral&) const;
bool operator!=(const nonliteral&) const;
bool operator>=(const nonliteral&) const;
bool operator>(const nonliteral&) const;
};
struct virtual_default_dtor {
virtual ~virtual_default_dtor() = default;
};
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<AllDeleted, string>>);
static_assert(is_default_constructible_v<variant<string, AllDeleted>>);
static_assert(is_default_constructible_v<variant<DeletedMoves>>);
static_assert(noexcept(variant<int>()));
static_assert(!noexcept(variant<Empty>()));
static_assert(noexcept(variant<DefaultNoexcept>()));
{
variant<virtual_default_dtor> a;
}
}
void copy_ctor()
{
static_assert(is_copy_constructible_v<variant<int, string>>);
static_assert(!is_copy_constructible_v<variant<AllDeleted, string>>);
static_assert(is_trivially_copy_constructible_v<variant<int>>);
static_assert(!is_trivially_copy_constructible_v<variant<std::string>>);
static_assert(is_trivially_copy_constructible_v<variant<DeletedMoves>>);
{
variant<int> a;
static_assert(noexcept(variant<int>(a)));
}
{
variant<string> a;
static_assert(!noexcept(variant<string>(a)));
}
{
variant<int, string> a;
static_assert(!noexcept(variant<int, string>(a)));
}
{
variant<int, char> a;
static_assert(noexcept(variant<int, char>(a)));
}
}
void move_ctor()
{
static_assert(is_move_constructible_v<variant<int, string>>);
static_assert(!is_move_constructible_v<variant<AllDeleted, string>>);
static_assert(is_move_constructible_v<variant<int, DeletedMoves>>); // uses copy ctor
static_assert(is_trivially_move_constructible_v<variant<int>>);
static_assert(!is_trivially_move_constructible_v<variant<std::string>>);
static_assert(!noexcept(variant<int, Empty>(declval<variant<int, Empty>>())));
static_assert(noexcept(variant<int, DefaultNoexcept>(declval<variant<int, DefaultNoexcept>>())));
}
void arbitrary_ctor()
{
static_assert(!is_constructible_v<variant<string, string>, const char*>);
static_assert(is_constructible_v<variant<int, string>, const char*>);
static_assert(noexcept(variant<int, Empty>(int{})));
static_assert(noexcept(variant<int, DefaultNoexcept>(int{})));
static_assert(!noexcept(variant<int, Empty>(Empty{})));
static_assert(noexcept(variant<int, DefaultNoexcept>(DefaultNoexcept{})));
// P0608R3 disallow narrowing conversions and boolean conversions
static_assert(!is_constructible_v<variant<float>, int>);
static_assert(!is_constructible_v<variant<float, vector<int>>, int>);
static_assert(is_constructible_v<variant<float, int>, char>);
static_assert(!is_constructible_v<variant<float, char>, int>);
static_assert(is_constructible_v<variant<float, long>, int>);
struct big_int { big_int(int) { } };
static_assert(is_constructible_v<variant<float, big_int>, int>);
static_assert(!is_constructible_v<variant<int>, unsigned>);
static_assert(!is_constructible_v<variant<bool>, int>);
static_assert(!is_constructible_v<variant<bool>, void*>);
// P1957R2 Converting from T* to bool should be considered narrowing
struct ConvertibleToBool
{
operator bool() const { return true; }
};
static_assert(is_constructible_v<variant<bool>, ConvertibleToBool>);
static_assert(is_constructible_v<variant<bool, int>, ConvertibleToBool>);
}
struct none { none() = delete; };
struct any { template <typename T> any(T&&) {} };
void in_place_index_ctor()
{
variant<string, string> a(in_place_index<0>, "a");
variant<string, string> b(in_place_index<1>, {'a'});
static_assert(!is_constructible_v<variant<none, any>, std::in_place_index_t<0>>, "PR libstdc++/90165");
}
void in_place_type_ctor()
{
variant<int, string, int> a(in_place_type<string>, "a");
variant<int, string, int> b(in_place_type<string>, {'a'});
static_assert(!is_constructible_v<variant<string, string>, in_place_type_t<string>, const char*>);
static_assert(!is_constructible_v<variant<none, any>, std::in_place_type_t<none>>, "PR libstdc++/90165");
}
void dtor()
{
static_assert(is_destructible_v<variant<int, string>>);
static_assert(is_destructible_v<variant<AllDeleted, string>>);
}
void copy_assign()
{
static_assert(is_copy_assignable_v<variant<int, string>>);
static_assert(!is_copy_assignable_v<variant<AllDeleted, string>>);
static_assert(is_trivially_copy_assignable_v<variant<int>>);
static_assert(!is_trivially_copy_assignable_v<variant<string>>);
static_assert(is_trivially_copy_assignable_v<variant<DeletedMoves>>);
{
variant<Empty> a;
static_assert(!noexcept(a = a));
}
{
variant<DefaultNoexcept> a;
static_assert(noexcept(a = a));
}
}
void move_assign()
{
static_assert(is_move_assignable_v<variant<int, string>>);
static_assert(!is_move_assignable_v<variant<AllDeleted, string>>);
static_assert(is_move_assignable_v<variant<int, DeletedMoves>>); // uses copy assignment
static_assert(is_trivially_move_assignable_v<variant<int>>);
static_assert(!is_trivially_move_assignable_v<variant<string>>);
{
variant<Empty> a;
static_assert(!noexcept(a = std::move(a)));
}
{
variant<DefaultNoexcept> a;
static_assert(noexcept(a = std::move(a)));
}
}
void arbitrary_assign()
{
static_assert(!is_assignable_v<variant<string, string>, const char*>);
static_assert(is_assignable_v<variant<int, string>, const char*>);
static_assert(noexcept(variant<int, Empty>() = int{}));
static_assert(noexcept(variant<int, DefaultNoexcept>() = int{}));
static_assert(!noexcept(variant<int, Empty>() = Empty{}));
static_assert(noexcept(variant<int, DefaultNoexcept>() = DefaultNoexcept{}));
}
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, 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()
{
{
constexpr variant<int, nonliteral> a(42), b(43);
static_assert((a < b));
static_assert(!(a > b));
static_assert((a <= b));
static_assert(!(a == b));
static_assert((a != b));
static_assert(!(a >= b));
}
{
constexpr variant<int, nonliteral> a(42), b(42);
static_assert(!(a < b));
static_assert(!(a > b));
static_assert((a <= b));
static_assert((a == b));
static_assert(!(a != b));
static_assert((a >= b));
}
{
constexpr variant<int, nonliteral> a(43), b(42);
static_assert(!(a < b));
static_assert((a > b));
static_assert(!(a <= b));
static_assert(!(a == b));
static_assert((a != b));
static_assert((a >= b));
}
{
constexpr monostate a, b;
static_assert(!(a < b));
static_assert(!(a > b));
static_assert((a <= b));
static_assert((a == b));
static_assert(!(a != b));
static_assert((a >= b));
}
}
// Not swappable, and variant<C> not swappable via the generic std::swap.
struct C { };
void swap(C&, C&) = delete;
static_assert( !std::is_swappable_v<variant<C>> );
static_assert( !std::is_swappable_v<variant<int, C>> );
static_assert( !std::is_swappable_v<variant<C, int>> );
// Not swappable, and variant<D> not swappable via the generic std::swap.
struct D { D(D&&) = delete; };
static_assert( !std::is_swappable_v<variant<D>> );
static_assert( !std::is_swappable_v<variant<int, D>> );
static_assert( !std::is_swappable_v<variant<D, int>> );
void test_swap()
{
static_assert(is_swappable_v<variant<int, string>>);
static_assert(!is_swappable_v<variant<MoveCtorOnly>>);
static_assert(is_swappable_v<variant<MoveCtorAndSwapOnly>>);
static_assert(!is_swappable_v<variant<AllDeleted>>);
}
void test_visit()
{
{
struct Visitor
{
void operator()(monostate) {}
void operator()(const int&) {}
};
struct CVisitor
{
void operator()(monostate) const {}
void operator()(const int&) const {}
};
}
{
struct Visitor
{
bool operator()(int, float) { return false; }
bool operator()(int, double) { return false; }
bool operator()(char, float) { return false; }
bool operator()(char, double) { return false; }
};
visit(Visitor(), variant<int, char>(), variant<float, double>());
}
{
struct Visitor
{
constexpr bool operator()(const int&) { return true; }
constexpr bool operator()(const nonliteral&) { return false; }
};
static_assert(visit(Visitor(), variant<int, nonliteral>(0)));
}
{
struct Visitor
{
constexpr bool operator()(const int&) { return true; }
constexpr bool operator()(const nonliteral&) { return false; }
};
static_assert(visit(Visitor(), variant<int, nonliteral>(0)));
}
// PR libstdc++/79513
{
std::variant<int> v [[gnu::unused]] (5);
std::visit([](int&){}, v);
std::visit([](int&&){}, std::move(v));
}
}
void test_constexpr()
{
constexpr variant<int> a;
static_assert(holds_alternative<int>(a));
constexpr variant<int, char> b(in_place_index<0>, int{});
static_assert(holds_alternative<int>(b));
constexpr variant<int, char> c(in_place_type<int>, int{});
static_assert(holds_alternative<int>(c));
constexpr variant<int, char> d(in_place_index<1>, char{});
static_assert(holds_alternative<char>(d));
constexpr variant<int, char> e(in_place_type<char>, char{});
static_assert(holds_alternative<char>(e));
constexpr variant<int, char> f(char{});
static_assert(holds_alternative<char>(f));
{
struct literal {
constexpr literal() = default;
};
constexpr variant<literal, nonliteral> v{};
constexpr variant<literal, nonliteral> v1{in_place_type<literal>};
constexpr variant<literal, nonliteral> v2{in_place_index<0>};
}
{
constexpr variant<int> a(42);
static_assert(get<0>(a) == 42);
}
{
constexpr variant<int, nonliteral> a(42);
static_assert(get<0>(a) == 42);
}
{
constexpr variant<nonliteral, int> a(42);
static_assert(get<1>(a) == 42);
}
{
constexpr variant<int> a(42);
static_assert(get<int>(a) == 42);
}
{
constexpr variant<int, nonliteral> a(42);
static_assert(get<int>(a) == 42);
}
{
constexpr variant<nonliteral, int> a(42);
static_assert(get<int>(a) == 42);
}
{
constexpr variant<int> a(42);
static_assert(get<0>(std::move(a)) == 42);
}
{
constexpr variant<int, nonliteral> a(42);
static_assert(get<0>(std::move(a)) == 42);
}
{
constexpr variant<nonliteral, int> a(42);
static_assert(get<1>(std::move(a)) == 42);
}
{
constexpr variant<int> a(42);
static_assert(get<int>(std::move(a)) == 42);
}
{
constexpr variant<int, nonliteral> a(42);
static_assert(get<int>(std::move(a)) == 42);
}
{
constexpr variant<nonliteral, int> a(42);
static_assert(get<int>(std::move(a)) == 42);
}
}
void test_pr77641()
{
struct X {
constexpr X() { }
};
constexpr std::variant<X> v1 = X{};
}
namespace adl_trap
{
struct X {
X() = default;
X(int) { }
X(std::initializer_list<int>, const X&) { }
};
template<typename T> void move(T&) { }
template<typename T> void forward(T&) { }
struct Visitor {
template<typename T> void operator()(T&&) { }
};
}
void test_adl()
{
using adl_trap::X;
X x;
std::initializer_list<int> il;
adl_trap::Visitor vis;
std::variant<X> v0(x);
v0 = x;
v0.emplace<0>(x);
v0.emplace<0>(il, x);
visit(vis, v0);
variant<X> v1{in_place_index<0>, x};
variant<X> v2{in_place_type<X>, x};
variant<X> v3{in_place_index<0>, il, x};
variant<X> v4{in_place_type<X>, il, x};
}
void test_variant_alternative()
{
static_assert(is_same_v<variant_alternative_t<0, variant<int, string>>, int>);
static_assert(is_same_v<variant_alternative_t<1, variant<int, string>>, string>);
static_assert(is_same_v<variant_alternative_t<0, const variant<int>>, const int>);
static_assert(is_same_v<variant_alternative_t<0, volatile variant<int>>, volatile int>);
static_assert(is_same_v<variant_alternative_t<0, const volatile variant<int>>, const volatile int>);
}
template<typename V, typename T>
constexpr auto has_type_emplace(int) -> decltype((declval<V>().template emplace<T>(), true))
{ return true; };
template<typename V, typename T>
constexpr bool has_type_emplace(...)
{ return false; };
template<typename V, size_t N>
constexpr auto has_index_emplace(int) -> decltype((declval<V>().template emplace<N>(), true))
{ return true; };
template<typename V, size_t T>
constexpr bool has_index_emplace(...)
{ return false; };
void test_emplace()
{
static_assert(has_type_emplace<variant<int>, int>(0));
static_assert(!has_type_emplace<variant<long>, int>(0));
static_assert(has_index_emplace<variant<int>, 0>(0));
static_assert(!has_type_emplace<variant<AllDeleted>, AllDeleted>(0));
static_assert(!has_index_emplace<variant<AllDeleted>, 0>(0));
static_assert(has_type_emplace<variant<int, AllDeleted>, int>(0));
static_assert(has_index_emplace<variant<int, AllDeleted>, 0>(0));
static_assert(has_type_emplace<variant<int, vector<int>, AllDeleted>, vector<int>>(0));
static_assert(has_index_emplace<variant<int, vector<int>, AllDeleted>, 1>(0));
// The above tests only check the emplace members are available for
// overload resolution. The following odr-uses will instantiate them:
variant<int, vector<int>, AllDeleted> v;
v.emplace<0>(1);
v.emplace<int>(1);
v.emplace<1>(1, 1);
v.emplace<vector<int>>(1, 1);
v.emplace<1>({1, 2, 3, 4});
v.emplace<vector<int>>({1, 2, 3, 4});
}
void test_triviality()
{
#define TEST_TEMPLATE(DT, CC, MC, CA, MA, CC_VAL, MC_VAL, CA_VAL, MA_VAL) \
{ \
struct A \
{ \
~A() DT; \
A(const A&) CC; \
A(A&&) MC; \
A& operator=(const A&) CA; \
A& operator=(A&&) MA; \
}; \
static_assert(CC_VAL == is_trivially_copy_constructible_v<variant<A>>); \
static_assert(MC_VAL == is_trivially_move_constructible_v<variant<A>>); \
static_assert(CA_VAL == is_trivially_copy_assignable_v<variant<A>>); \
static_assert(MA_VAL == is_trivially_move_assignable_v<variant<A>>); \
}
TEST_TEMPLATE(=default, =default, =default, =default, =default, true, true, true, true)
TEST_TEMPLATE(=default, =default, =default, =default, , true, true, true, false)
TEST_TEMPLATE(=default, =default, =default, , =default, true, true, false, true)
TEST_TEMPLATE(=default, =default, =default, , , true, true, false, false)
TEST_TEMPLATE(=default, =default, , =default, =default, true, false, true, false)
TEST_TEMPLATE(=default, =default, , =default, , true, false, true, false)
TEST_TEMPLATE(=default, =default, , , =default, true, false, false, false)
TEST_TEMPLATE(=default, =default, , , , true, false, false, false)
TEST_TEMPLATE(=default, , =default, =default, =default, false, true, false, true)
TEST_TEMPLATE(=default, , =default, =default, , false, true, false, false)
TEST_TEMPLATE(=default, , =default, , =default, false, true, false, true)
TEST_TEMPLATE(=default, , =default, , , false, true, false, false)
TEST_TEMPLATE(=default, , , =default, =default, false, false, false, false)
TEST_TEMPLATE(=default, , , =default, , false, false, false, false)
TEST_TEMPLATE(=default, , , , =default, false, false, false, false)
TEST_TEMPLATE(=default, , , , , false, false, false, false)
TEST_TEMPLATE( , =default, =default, =default, =default, false, false, false, false)
TEST_TEMPLATE( , =default, =default, =default, , false, false, false, false)
TEST_TEMPLATE( , =default, =default, , =default, false, false, false, false)
TEST_TEMPLATE( , =default, =default, , , false, false, false, false)
TEST_TEMPLATE( , =default, , =default, =default, false, false, false, false)
TEST_TEMPLATE( , =default, , =default, , false, false, false, false)
TEST_TEMPLATE( , =default, , , =default, false, false, false, false)
TEST_TEMPLATE( , =default, , , , false, false, false, false)
TEST_TEMPLATE( , , =default, =default, =default, false, false, false, false)
TEST_TEMPLATE( , , =default, =default, , false, false, false, false)
TEST_TEMPLATE( , , =default, , =default, false, false, false, false)
TEST_TEMPLATE( , , =default, , , false, false, false, false)
TEST_TEMPLATE( , , , =default, =default, false, false, false, false)
TEST_TEMPLATE( , , , =default, , false, false, false, false)
TEST_TEMPLATE( , , , , =default, false, false, false, false)
TEST_TEMPLATE( , , , , , false, false, false, false)
#undef TEST_TEMPLATE
#define TEST_TEMPLATE(CC, MC, CA, MA) \
{ \
struct A \
{ \
A(const A&) CC; \
A(A&&) MC; \
A& operator=(const A&) CA; \
A& operator=(A&&) MA; \
}; \
static_assert(!is_trivially_copy_constructible_v<variant<AllDeleted, A>>); \
static_assert(!is_trivially_move_constructible_v<variant<AllDeleted, A>>); \
static_assert(!is_trivially_copy_assignable_v<variant<AllDeleted, A>>); \
static_assert(!is_trivially_move_assignable_v<variant<AllDeleted, A>>); \
}
TEST_TEMPLATE(=default, =default, =default, =default)
TEST_TEMPLATE(=default, =default, =default, )
TEST_TEMPLATE(=default, =default, , =default)
TEST_TEMPLATE(=default, =default, , )
TEST_TEMPLATE(=default, , =default, =default)
TEST_TEMPLATE(=default, , =default, )
TEST_TEMPLATE(=default, , , =default)
TEST_TEMPLATE(=default, , , )
TEST_TEMPLATE( , =default, =default, =default)
TEST_TEMPLATE( , =default, =default, )
TEST_TEMPLATE( , =default, , =default)
TEST_TEMPLATE( , =default, , )
TEST_TEMPLATE( , , =default, =default)
TEST_TEMPLATE( , , =default, )
TEST_TEMPLATE( , , , =default)
TEST_TEMPLATE( , , , )
#undef TEST_TEMPLATE
static_assert(is_trivially_copy_constructible_v<variant<DefaultNoexcept, int, char, float, double>>);
static_assert(is_trivially_move_constructible_v<variant<DefaultNoexcept, int, char, float, double>>);
static_assert(is_trivially_copy_assignable_v<variant<DefaultNoexcept, int, char, float, double>>);
static_assert(is_trivially_move_assignable_v<variant<DefaultNoexcept, int, char, float, double>>);
}