If the lambda or function doesn't store the pointer, then pass the shared_ptr by reference to avoid invoking the copy constructor for each element. C++ Afrita void use_shared_ptr_by_value(shared_ptr<int> sp); void use_shared_ptr_by_reference(shared_ptr<int>& sp); void use_shared_...
explicit _Sp_counted_ptr(_Ptr __p) noexcept //之所以没有使用forward构造函数,是因为如果已经明确知道参数将是一个指针类型,pass by value是最安全也应该是最高效果的 : _M_ptr(__p) { } virtual void _M_destroy() noexcept { delete this; } virtual void* _M_get_deleter(const std::type_info...
1.We can think of a shared_ptr as if it has an associated counter, usually referred to as areference count. Counterincrementedwhen: use it(shared_ptr) asthe right-hand operand of an assignment(copy); passit to orreturnitfrom a function by value. Counterdecrementedwhen: assign a new vale...
原文链接 https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#cp31-pass-small-amounts-of-data-between-threads-by-value-rather-than-by-reference-or-pointer 本文参与腾讯云自媒体同步曝光计划,分享自微信公众号。
https:///isocpp/CppCoreGuidelines/blob/master/#cp31-pass-small-amounts-of-data-between-threads-by-value-rather-than-by-reference-or-pointer 新书介绍 以下是本人3月份出版的新书,拜托多多关注! 本书利用Python 的标准GUI 工具包tkinter,通过可执行的示例对23 个设计模式逐个进行说明。这样...
Resurrect DeleteNode(), but make it take an r-value shared_ptr and assert that use_count() == 1. Avoid adding ~CNode() and CNode::m_destruct_cb along with sending it in everywhere in the constructor. This means we don't need to touch 5 of the test files. master...hodlinator:bit...
for a std::weak_ptr to be left pointing to a resource that has been deallocated by a std::shared_ptr. However, std::weak_ptr has a neat trick up its sleeve -- because it has access to the reference count for an object, it can determine if it is pointing to a valid object or ...
The reference counter of this shared_ptr<shared_ptr<T>> // will normally only be modified from this thread, which avoids // cache line bouncing. (Though the caller is free to pass the pointer // to other threads and bump reference counter from there) // // Then this shared_ptr...
<int> sp); void use_shared_ptr_by_reference(shared_ptr<int>& sp); void use_shared_ptr_by_const_reference(const shared_ptr<int>& sp); void use_raw_pointer(int* p); void use_reference(int& r); void test() { auto sp = make_shared<int>(5); // Pass the shared_ptr by value...
or a reference to the underlying object.use_raw_pointer(sp.get()); use_reference(*sp);// Pass the shared_ptr by value.// This invokes the move constructor, which doesn't increment the reference count// but in fact transfers ownership to the callee.use_shared_ptr_by_value(move(sp));...