NAME¶

std::uses_allocator - std::uses_allocator

Synopsis¶

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.

Member constants¶

value true
[static] (public static member constant)

Member functions¶

operator bool converts the object to bool, returns value
(public member function)
operator() returns value
(C++14) (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 checks if the specified type supports uses-allocator construction
(C++11) (class template)