MySQL 8.0.29
Source Code Documentation
default_init_allocator.h
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1/*
2 Copyright (c) 2020, 2021, Oracle and/or its affiliates.
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24
25#ifndef MYSQL_HARNESS_DEFAULT_INIT_ALLOCATOR_H_
26#define MYSQL_HARNESS_DEFAULT_INIT_ALLOCATOR_H_
27
28#include <memory>
29
30/**
31 * allocator which leaves newly constructed fields "default initialized".
32 *
33 * in case of std::vector<int> after a resize() the newly added fields would
34 * be uninitialized.
35 *
36 * useful in case of network-buffers it will be read() into right afterwards.
37 */
38template <class T, class A = std::allocator<T>>
39class default_init_allocator : public A {
40 using a_t = std::allocator_traits<A>;
41
42 public:
43 template <class U>
44 struct rebind {
45 using other =
47 };
48
49 // inherit the constructors of the allocator
50 using A::A;
51
52 template <class U>
53 void construct(U *ptr) noexcept(
54 std::is_nothrow_default_constructible<U>::value) {
55 ::new (static_cast<void *>(ptr)) U;
56 }
57 template <class U, class... Args>
58 void construct(U *ptr, Args &&... args) {
59 a_t::construct(static_cast<A &>(*this), ptr, std::forward<Args>(args)...);
60 }
61};
62
63#endif
allocator which leaves newly constructed fields "default initialized".
Definition: default_init_allocator.h:39
void construct(U *ptr, Args &&... args)
Definition: default_init_allocator.h:58
void construct(U *ptr) noexcept(std::is_nothrow_default_constructible< U >::value)
Definition: default_init_allocator.h:53
std::allocator_traits< A > a_t
Definition: default_init_allocator.h:40
#define U
Definition: ctype-tis620.cc:74
void construct(void *mem, size_t offset, Tuple &&tuple)
Definition: ut0new.h:52
Definition: default_init_allocator.h:44
Definition: dtoa.cc:594