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std::experi...ope_success(3) C++ Standard Libary std::experi...ope_success(3) NAME std::experimental::scope_success - std::experimental::scope_success Synopsis Defined in header <experimental/scope> template<class EF> (library fundamentals TS v3) class scope_success; The class template scope_success is a general-purpose scope guard intended to call its exit function when a scope is normally exited. scope_success is not CopyConstructible, CopyAssignable or MoveAs- signable, however, it may be MoveConstructible if EF meets some requirements, which permits wrapping a scope_success into another object. A scope_success may be either active, i.e. calls its exit function on destruction, or inactive, i.e. does nothing on destruction. A scope_success is active after constructed from an exit function. A scope_success can become inactive by calling release() on it ei- ther manually or automatically (by the move constructor). An inactive scope_success may also be obtained by initializing with another inactive scope_success. Once a scope_success is inactive, it cannot become active again. A scope_success effectively holds an EF and a bool flag indicating if it is active, alongwith a counter of uncaught exceptions used for detecting whether the destructor is called during stack unwinding. Template parameters EF - type of stored exit func- tion Type requirements - EF shall be either: * a Destructible FunctionObject type * an lvalue reference to FunctionObject * an lvalue reference to function - Calling an lvalue of std::remove_reference_t<EF> with no argument shall be well-formed. Member functions constructor constructs a new scope_success (public member function) calls the exit function when the scope is exited nor- mally if the destructor scope_success is active, then destroys the scope_suc- cess (public member function) operator= scope_success is not assignable [deleted] (public member function) Modifiers release makes the scope_success inactive (public member function) Deduction guides Notes Constructing a scope_success of dynamic storage duration might lead to unexpected behavior. Constructing a scope_success is constructed from another scope_suc- cess created in a different thread might also lead to unexpected behavior since the count of uncaught exceptions obtained in different threads may be compared during the destruction. If the EF stored in a scope_success object refers to a local vari- able of the function where it is defined, e.g., as a lambda capturing the vari- able by reference, and that variable is used as a return operand in that function, that variable might have already been returned when the scope_success's destructor exe- cutes, calling the exit function. This can lead to surprising behavior. Example This section is incomplete Reason: no example See also scope_exit wraps a function object and invokes it on exiting the scope (class template) wraps a function object and invokes it on exiting the scope through scope_fail an exception (class template) default_delete default deleter for unique_ptr (C++11) (class template) http://cppreference.com 2022.07.31 std::experi...ope_success(3)
NAME | Synopsis | Template parameters | Type requirements | Member functions | Modifiers | Notes | Example | See also
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