std::shared_ptr<T>::get

 

C++

编译器支持

独立和托管

语言

标准库

标准库头文件

命名需求

功能测试宏 (C++20)

语言支持库

概念库 (C++20)

元编程库 (C++11)

诊断库

通用实用程序库

字符串库

容器库

迭代器库

范围库 (C++20)

算法库

数值库

本地化库

输入/输出库

文件系统库 (C++17)

正则表达式库 (C++11)

并发支持库 (C++11)

执行支持库 (C++26)

技术规范

符号索引

外部库

 

实用程序库

语言支持 类型支持 (基本类型，RTTI) 库功能测试宏 (C++20) 动态内存管理 程序实用程序 协程支持 (C++20) 可变参数函数 is_constant_evaluated (C++20) is_within_lifetime (C++26) initializer_list (C++11) source_location (C++20) 调试支持 is_debugger_present (C++26) breakpoint_if_debugging (C++26) breakpoint (C++26) 三向比较 three_way_comparablethree_way_comparable_with (C++20)(C++20) strong_ordering (C++20) weak_ordering (C++20) partial_ordering (C++20) common_comparison_category (C++20) compare_three_way_result (C++20) compare_three_way (C++20) strong_order (C++20) weak_order (C++20) partial_order (C++20) compare_strong_order_fallback (C++20) compare_weak_order_fallback (C++20) compare_partial_order_fallback (C++20)    is_eqis_ltis_lteq (C++20)(C++20)(C++20) is_neqis_gtis_gteq (C++20)(C++20)(C++20)

通用实用程序 日期和时间 函数对象 格式化库 (C++20) bitset hash (C++11) 关系运算符 (C++20 中已弃用) rel_ops::operator!=rel_ops::operator>     rel_ops::operator<=rel_ops::operator>= 整数比较函数 cmp_equalcmp_lesscmp_less_than (C++20)(C++20)(C++20)    cmp_not_equalcmp_greatercmp_greater_than (C++20)(C++20)(C++20) in_range (C++20) 交换 和 类型操作 swap ranges::swap (C++20) exchange (C++14) declval (C++11) to_underlying (C++23) forward (C++11) forward_like (C++23) move (C++11) move_if_noexcept (C++11) as_const (C++17) 通用词汇类型 pair tuple (C++11) optional (C++17) any (C++17) variant (C++17) tuple_size (C++11) tuple_element (C++11) apply (C++17) make_from_tuple (C++17) expected (C++23) 基本字符串转换 to_chars (C++17) from_chars (C++17) chars_format (C++17) to_chars_result (C++17) from_chars_result (C++17)

 

动态内存管理

未初始化内存算法 uninitialized_copy uninitialized_fill uninitialized_move (C++17) uninitialized_default_construct (C++17) uninitialized_value_construct (C++17) destroy (C++17) destroy_at (C++17) voidify (C++20) uninitialized_copy_n (C++11) uninitialized_fill_n uninitialized_move_n (C++17) uninitialized_default_construct_n (C++17) uninitialized_value_construct_n (C++17) destroy_n (C++17) construct_at (C++20) 约束的未初始化内存算法 ranges::uninitialized_copy (C++20) ranges::uninitialized_fill (C++20) ranges::uninitialized_move (C++20) ranges::construct_at (C++20) ranges::destroy (C++20) ranges::destroy_n (C++20) ranges::destroy_at (C++20) ranges::uninitialized_copy_n (C++20) ranges::uninitialized_fill_n (C++20) ranges::uninitialized_move_n (C++20) ranges::uninitialized_default_construct (C++20) ranges::uninitialized_value_construct (C++20) ranges::uninitialized_default_construct_n (C++20)   ranges::uninitialized_value_construct_n (C++20) 分配器 allocator allocator_traits (C++11) allocation_result (C++23) allocator_arg (C++11) uses_allocator (C++11) uses_allocator_construction_args (C++20) make_obj_using_allocator (C++20) uninitialized_construct_using_allocator (C++20) scoped_allocator_adaptor (C++11) pmr::polymorphic_allocator (C++17) 内存资源 pmr::memory_resource (C++17) pmr::get_default_resource (C++17) pmr::set_default_resource (C++17) pmr::new_delete_resource (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) pmr::pool_options (C++17) 垃圾回收支持 declare_reachable (C++11)(直到 C++23) undeclare_reachable (C++11)(直到 C++23) declare_no_pointers (C++11)(直到 C++23) undeclare_no_pointers (C++11)(直到 C++23) pointer_safety (C++11)(直到 C++23) get_pointer_safety (C++11)(直到 C++23) 未初始化存储 raw_storage_iterator (直到 C++20*) get_temporary_buffer (直到 C++20*) return_temporary_buffer (直到 C++20*) 显式生命周期管理 start_lifetime_asstart_lifetime_as_array (C++23)(C++23)

智能指针 unique_ptr (C++11) shared_ptr (C++11) weak_ptr (C++11) auto_ptr (直到 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) 低级内存 管理 operator new operator new[] operator delete operator delete[] get_new_handler (C++11) set_new_handler launder (C++17) bad_alloc bad_array_new_length (C++11) nothrow_t align_val_t (C++17) destroying_delete_t (C++20) new_handler nothrow 其他 pointer_traits (C++11) to_address (C++20) addressof (C++11) align (C++11) assume_aligned (C++20) C 库 malloc calloc realloc    aligned_alloc (C++17) free

 

std::shared_ptr

成员函数

shared_ptr::shared_ptr

shared_ptr::~shared_ptr

shared_ptr::operator=

修改器

shared_ptr::reset

shared_ptr::swap

观察者

shared_ptr::get

shared_ptr::operator*shared_ptr::operator->

shared_ptr::operator[] (C++17)

shared_ptr::use_count

shared_ptr::unique (直到 C++20*)

shared_ptr::operator bool

shared_ptr::owner_before

shared_ptr::owner_hash (C++26)

shared_ptr::owner_equal (C++26)

非成员函数

swap(std::shared_ptr)

make_sharedmake_shared_for_overwrite (C++20)

allocate_sharedallocate_shared_for_overwrite (C++20)

static_pointer_castdynamic_pointer_castconst_pointer_castreinterpret_pointer_cast (C++17)

get_deleter

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

operator<<

atomic_xxx 函数 (直到 C++26*)

辅助类

atomic<std::shared_ptr> (C++20)

hash<std::shared_ptr>

推导指南(C++17)

 

T* get() const noexcept;		(直到 C++17)
element_type* get() const noexcept;		(自 C++17 起)

返回存储的指针。

参数

(无)

返回值

存储的指针。

备注

shared_ptr 可能共享对对象的拥有权，同时存储指向另一个对象的指针。get() 返回存储的指针，而不是管理的指针。

示例

运行此代码

#include <iostream>
#include <memory>
#include <string_view>
 
int main()
{
    auto output = [](std::string_view msg, int const* pInt)
    {
        std::cout << msg << *pInt << " in " << pInt << '\n';
    };
 
    int* pInt = new int(42);
    std::shared_ptr<int> pShared = std::make_shared<int>(42);
 
    output("Naked pointer: ", pInt);
//  output("Shared pointer: ", pShared); // compiler error
    output("Shared pointer: ", &*pShared); // OK, calls operator*, then takes addr
    output("Shared pointer with get(): ", pShared.get());
 
    delete pInt;
 
    std::cout << "\nThe shared_ptr's aliasing constructor demo.\n";
    struct Base1 { int i1{}; };
    struct Base2 { int i2{}; };
    struct Derived : Base1, Base2 { int i3{}; };
 
    std::shared_ptr<Derived> p(new Derived());
    std::shared_ptr<Base2> q(p, static_cast<Base2*>(p.get()));
    std::cout << "q shares ownership with p, but points to Base2 subobject:\n"
              << "p.get(): " << p.get() << '\n'
              << "q.get(): " << q.get() << '\n'
              << "&(p->i1): " << &(p->i1) << '\n'
              << "&(p->i2): " << &(p->i2) << '\n'
              << "&(p->i3): " << &(p->i3) << '\n'
              << "&(q->i2): " << &(q->i2) << '\n';
}

可能的输出

Naked pointer: 42 in 0xacac20
Shared pointer: 42 in 0xacac50
Shared pointer with get(): 42 in 0xacac50
 
The shared_ptr's aliasing constructor demo.
q shares ownership with p, but points to Base2 subobject:
p.get(): 0xacac20
q.get(): 0xacac24
&(p->i1): 0xacac20
&(p->i2): 0xacac24
&(p->i3): 0xacac28
&(q->i2): 0xacac24

另请参阅

operator*operator->

解除对存储的指针的引用 (公共成员函数)