std::uses_allocator<std::tuple>

 

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std::tuple

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operator==operator!=operator<operator<=operator>operator>=operator<=> (until C++20)(until C++20)(until C++20)(until C++20)(until C++20)(C++20)

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tuple-like (C++23)

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tuple_size<std::tuple>

tuple_element<std::tuple>

uses_allocator<std::tuple>

basic_common_reference<std::tuple> (C++23)

common_type<std::tuple> (C++23)

formatter<std::tuple> (C++23)

ignore

Deduction guides(C++17)

 

Defined in header <tuple>
template< class... Types, class Alloc > struct uses_allocator< std::tuple<Types...>, Alloc > : std::true_type { };		(since C++11)

This specialization of std::uses_allocator informs other library components that tuples support uses-allocator construction, even though they do not have a nested allocator_type.

Inherited from std::integral_constant

Member constants

value [static]

true (public static member constant)

Member functions

operator bool	converts the object to bool, returns value (public member function)
operator() (C++14)	returns value (public member function)

Member types

Type	Definition
value_type	bool
type	std::integral_constant<bool, value>

Example

/ myalloc is a stateful Allocator with a single-argument constructor
/ that takes an int. It has no default constructor.
 
    using innervector_t = std::vector<int, myalloc<int>>;
    using elem_t = std::tuple<int, innervector_t>;
    using Alloc = std::scoped_allocator_adaptor< myalloc<elem_t>, myalloc<int>>;
 
    Alloc a(1,2);
    std::vector<elem_t, Alloc> v(a);
    v.resize(1);                  / uses allocator #1 for elements of v
    std::get<1>(v[0]).resize(10); / uses allocator #2 for innervector_t

See also

uses_allocator (C++11)

checks if the specified type supports uses-allocator construction (class template)

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