Difference between revisions of "cpp/memory/unique ptr/get deleter"
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< cpp | memory | unique ptr
m (merge noexcept) |
Andreas Krug (Talk | contribs) m (fmt) |
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{{cpp/memory/unique_ptr/navbar}} | {{cpp/memory/unique_ptr/navbar}} | ||
{{dcl begin}} | {{dcl begin}} | ||
| − | {{dcl | since=c++11 | 1= | + | {{dcl|since=c++11|notes={{mark|constexpr since C++23}}|1= |
| − | + | Deleter& get_deleter() noexcept; | |
}} | }} | ||
| − | {{dcl | since=c++11 | 1= | + | {{dcl|since=c++11|notes={{mark|constexpr since C++23}}|1= |
const Deleter& get_deleter() const noexcept; | const Deleter& get_deleter() const noexcept; | ||
}} | }} | ||
| Line 19: | Line 19: | ||
===Example=== | ===Example=== | ||
| − | {{example | + | {{example |
| − | + | |code= | |
#include <iostream> | #include <iostream> | ||
#include <memory> | #include <memory> | ||
| Line 26: | Line 26: | ||
struct Foo | struct Foo | ||
{ | { | ||
| − | Foo() { std::cout << "Foo | + | Foo() { std::cout << "Foo() 0x" << std::hex << (void*)this << '\n'; } |
| − | ~Foo() { std::cout << "~Foo | + | ~Foo() { std::cout << "~Foo() 0x" << std::hex << (void*)this << '\n'; } |
}; | }; | ||
struct D | struct D | ||
{ | { | ||
| − | void bar() { std::cout << " | + | int number; |
| + | |||
| + | void bar() | ||
| + | { | ||
| + | std::cout << "call D::bar(), my number is: " << std::dec << number << '\n'; | ||
| + | } | ||
| + | |||
void operator()(Foo* p) const | void operator()(Foo* p) const | ||
{ | { | ||
| − | std::cout << " | + | std::cout << "call deleter for Foo object 0x" << std::hex << (void*)p << '\n'; |
delete p; | delete p; | ||
} | } | ||
| Line 42: | Line 48: | ||
int main() | int main() | ||
{ | { | ||
| − | std::unique_ptr<Foo, D> | + | std::cout << "main start\n"; |
| − | D& | + | |
| − | + | std::unique_ptr<Foo, D> up1(new Foo(), D(42)); | |
| + | D& del1 = up1.get_deleter(); | ||
| + | del1.bar(); | ||
| + | |||
| + | std::unique_ptr<Foo, D> up2(new Foo(), D(43)); | ||
| + | D& del2 = up2.get_deleter(); | ||
| + | auto* released = up2.release(); | ||
| + | del2(released); | ||
| + | |||
| + | std::cout << "main end\n"; | ||
} | } | ||
| − | + | |output= | |
| − | Foo | + | main start |
| − | + | Foo() 0x0x90cc30 | |
| − | + | call D::bar(), my number is: 42 | |
| − | ~Foo | + | Foo() 0x0x90cc50 |
| + | call deleter for Foo object 0x0x90cc50 | ||
| + | ~Foo() 0x0x90cc50 | ||
| + | main end | ||
| + | call deleter for Foo object 0x0x90cc30 | ||
| + | ~Foo() 0x0x90cc30 | ||
}} | }} | ||
| − | + | ===See also=== | |
| − | + | {{dsc begin}} | |
| − | + | {{dsc inc|cpp/memory/shared_ptr/dsc get_deleter}} | |
| − | + | {{dsc end}} | |
| − | + | ||
| − | + | {{langlinks|de|es|fr|it|ja|pt|ru|zh}} | |
| − | + | ||
| − | + | ||
Latest revision as of 10:43, 10 October 2023
| Deleter& get_deleter() noexcept; |
(since C++11) (constexpr since C++23) |
|
| const Deleter& get_deleter() const noexcept; |
(since C++11) (constexpr since C++23) |
|
Returns the deleter object which would be used for destruction of the managed object.
Contents |
[edit] Parameters
(none)
[edit] Return value
The stored deleter object.
[edit] Example
Run this code
#include <iostream> #include <memory> struct Foo { Foo() { std::cout << "Foo() 0x" << std::hex << (void*)this << '\n'; } ~Foo() { std::cout << "~Foo() 0x" << std::hex << (void*)this << '\n'; } }; struct D { int number; void bar() { std::cout << "call D::bar(), my number is: " << std::dec << number << '\n'; } void operator()(Foo* p) const { std::cout << "call deleter for Foo object 0x" << std::hex << (void*)p << '\n'; delete p; } }; int main() { std::cout << "main start\n"; std::unique_ptr<Foo, D> up1(new Foo(), D(42)); D& del1 = up1.get_deleter(); del1.bar(); std::unique_ptr<Foo, D> up2(new Foo(), D(43)); D& del2 = up2.get_deleter(); auto* released = up2.release(); del2(released); std::cout << "main end\n"; }
Output:
main start Foo() 0x0x90cc30 call D::bar(), my number is: 42 Foo() 0x0x90cc50 call deleter for Foo object 0x0x90cc50 ~Foo() 0x0x90cc50 main end call deleter for Foo object 0x0x90cc30 ~Foo() 0x0x90cc30
[edit] See also
| returns the deleter of specified type, if owned (function template) |
