std::polymorphic<T, Allocator>::valueless_after_move

 

C++

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Feature test macros (C++20)

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Concepts library (C++20)

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Technical specifications

Symbols index

External libraries

 

Memory management library

Allocators allocator allocator_traits (C++11) allocation_result (C++23) scoped_allocator_adaptor (C++11) allocator_arg (C++11) uses_allocator (C++11) uses_allocator_construction_args (C++20) make_obj_using_allocator (C++20) pmr::polymorphic_allocator (C++17) uninitialized_construct_using_allocator (C++20) Memory resources pmr::memory_resource (C++17) pmr::get_default_resource (C++17)     pmr::set_default_resource (C++17) pmr::new_delete_resource (C++17) pmr::pool_options (C++17) pmr::null_memory_resource (C++17) pmr::synchronized_pool_resource (C++17) pmr::unsynchronized_pool_resource (C++17)     pmr::monotonic_buffer_resource (C++17) Explicit lifetime management start_lifetime_as (C++23) start_lifetime_as_array (C++23) Types for composite class design indirect (C++26) polymorphic (C++26) Miscellaneous pointer_traits (C++11) to_address (C++20) addressof (C++11) align (C++11) assume_aligned (C++20) is_sufficiently_aligned (C++26) C Library malloc      free calloc realloc aligned_alloc (C++17) free_sized (C++26) free_aligned_sized (C++26) memalignment (C++26) Uninitialized storage (until C++20*) raw_storage_iterator get_temporary_buffer return_temporary_buffer Garbage collector support (until C++23) declare_reachable (C++11) declare_no_pointers (C++11) pointer_safety (C++11) undeclare_reachable (C++11) undeclare_no_pointers (C++11) get_pointer_safety (C++11)

Specialized <memory> algorithms Low level memory management operator newoperator new[] operator deleteoperator delete[] nothrow nothrow_t new_handler set_new_handler get_new_handler (C++11) bad_alloc bad_array_new_length (C++11) align_val_t (C++17) destroying_delete_t (C++20) launder (C++17) Smart pointers unique_ptr (C++11) shared_ptr (C++11) weak_ptr (C++11) auto_ptr (until C++17*) owner_less (C++11) owner_less<void> (C++17) owner_hash (C++26) owner_equal (C++26) enable_shared_from_this (C++11) bad_weak_ptr (C++11) default_delete (C++11) out_ptr_t (C++23) inout_ptr_t (C++23)

 

std::polymorphic

Member functions

polymorphic::polymorphic

polymorphic::~polymorphic

polymorphic::operator=

Observers

polymorphic::operator->polymorphic::operator*

polymorphic::valueless_after_move

polymorphic::get_allocator

Modifiers

polymorphic::swap

Non-member functions

swap(std::polymorphic)

 

constexpr bool valueless_after_move() const noexcept;		(since C++26)

Checks whether *this is valueless.

Return value

true if *this is valueless, otherwise false.