1)移动赋值运算符。从r转移所有权到*this,如同在调用reset(r.release())后立即将std::forward<Deleter>(r.get_deleter())赋给get_deleter()。 此重载只有在std::is_move_assignable<Deleter>::value是true时才会参与重载决议。 如果Deleter不是引用类型,那么在以下情况下行为未定义: ...
std::shared_ptr<void> shared_ref_count((void*)0, [](void*){ // end }); for(int i = 0; i < 5; i++){ auto callback = base::Bind([shared_ref_count](){}); auto flow = new SearchFlow(callback); flow->Search(key); } 别忘了,std::shared_ptr的构造函数中提供了一个Delet...
此构造函数仅若 std::is_move_constructible<Deleter>::value 为true 才参与重载决议。若 Deleter 不是引用类型,则要求它为不抛出可移动构造 (MoveConstructible) (若 Deleter 是引用,则 get_deleter() 和u.get_deleter() 在移动构造后引用相同值)。
#include <iostream>#include <memory>structFoo{inti;};voidfoo_deleter(Foo*p){std::cout<<"foo_deleter called!\n";delete p;}intmain(){std::shared_ptr<int>aptr;{// 创建拥有一个 Foo 和删除器的 shared_ptrautofoo_p=new Foo;std::shared_ptr<Foo>r(foo_p, foo_deleter);aptr=std::share...
std::cout <<"Deleting Widget with custom deleter\n";deletep; };intmain(){// 删除器是类型的一部分std::unique_ptr<Widget,decltype(loggingDel)>upw(newWidget, loggingDel);// 使用 std::unique_ptr 时,类型包含了删除器的信息return0;
若std::unique_ptr<Y, D>::pointer 为指向字符类型的指针(例如当 Y 为char 或 char[] 或 CharT 时),这可能最终调用 operator<< 对空终止字符串的重载(若该指针实际上不指向这种字符串,则导致未定义行为),而非打印指针值自身的重载。 示例运行此代码 #include <iostream> #include <memory> class Foo {...
other-anotherunique_ptrobject to swap the managed object and the deleter with Return value (none) Example Run this code #include <iostream>#include <memory>structFoo{Foo(int_val):val(_val){std::cout<<"Foo...\n";}~Foo(){std::cout<<"~Foo...\n";}intval;};intmain(){std::unique...
std::unique_ptr<T,Deleter>::release pointer release()noexcept; (since C++11) (constexpr since C++23) Releases the ownership of the managed object, if any. get()returnsnullptrafter the call. The caller is responsible for cleaning up the object (e.g. by use ofget_deleter()). ...
指向被管理对象的指针,无被管理对象,则为nullptr。 示例 运行此代码 #include <iostream>#include <string>#include <memory>intmain(){std::unique_ptr<std::string>s_p(newstd::string("Hello, world!"));std::string*s=s_p.get();std::cout<<*s<<'\n';} ...
C++ std::unique_ptr deleter syntaxAsk Question Asked today Modified today Viewed 3 times 0 I'm trying to understand what int(*)(FILE*) mean here - how should I understand this syntax? The header of fclose is just int fclose(FILE* file), where does the (*) come from in the template...