Difference between revisions of "cpp/named req/Erasable"
(note why this is important (container requirement) and that arrays are not acceptable.) |
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===Notes=== | ===Notes=== | ||
| − | All [[cpp/container|standard library containers]] require that their element type satisfies | + | All [[cpp/container|standard library containers]] require that their element type satisfies Erasable. |
With the default allocator, this requirement is equivalent to the validity of {{c|p->~T()}}, which accepts class types with accessible destructors and all scalar types, but rejects array types, function types, reference types, and void. | With the default allocator, this requirement is equivalent to the validity of {{c|p->~T()}}, which accepts class types with accessible destructors and all scalar types, but rejects array types, function types, reference types, and void. | ||
Revision as of 02:05, 30 December 2015
Template:cpp/concept/title Template:cpp/concept/navbar
Specifies that an object of the type can be destroyed by a given Template:concept.
Requirements
The type T is Template:concept from the Template:concept X whose value_type is identical to T if, given
A
|
an allocator type |
m
|
an lvalue of type A
|
p
|
the pointer of type T* prepared by the container
|
where X::allocator_type is identical to std::allocator_traits<A>::rebind_alloc<T>,
the following expression is well-formed:
std::allocator_traits<A>::destroy(m, p);
If X is not allocator-aware, the term is defined as if A were std::allocator<T>, except that no allocator object needs to be created, and user-defined specializations of std::allocator are not instantiated.
Notes
All standard library containers require that their element type satisfies Erasable.
With the default allocator, this requirement is equivalent to the validity of p->~T(), which accepts class types with accessible destructors and all scalar types, but rejects array types, function types, reference types, and void.
See Also
| Template:concept | |
| Template:concept | |
| Template:concept | |
| Template:concept |
