dynamic exception specification

throw( )

?

(deprecated in c++11)

1) Non-throwing dynamic exception specification

(until C++17)

Potential exceptions Each function f, pointer to function fp, and pointer to member function mfp has a set of potential exceptions, which consists of types that might be thrown. Set of all types indicates that any exception may be thrown. This set is defined as follows: 1) If the declaration of f, fp, or mfp uses throw()(deprecated) or noexcept, the set is empty. 2) Otherwise, if the declaration of f, fp, or mfp uses a dynamic exception specification(deprecated), the set consists of the types listed in that specification 3) Otherwise, the set is the set of all types Note: for implicitly-declared special member functions (constructors, assignment operators, and destructors) and for the inheriting constructors, the set of potential exceptions is a combination of the sets of the potential exceptions of everything they would call: constructors/assignment operators/destructors of non-variant non-static data members, direct bases, and, where appropriate, virtual bases (including default argument expressions, as always). Each expression e has a set of potential exceptions, defined as follows: 1) If e is a core constant expression, the set is empty 2) Otherwise, the set is the union of the sets of potential exceptions of all immediate subexpressions of e (including default argument expressions), combined with another set that depends on the form of e, as follows: 1) If e is a function call expression, and the function is named by an id-expression (either directly or as part of member access or pointer-to-member access expression), the set of potential exceptions of the named function is added to the list. if the function is named by an expression of type noexcept function or by an expression of type pointer to noexcept function, the set is empty otherwise, the set is the set of all types 2) If e calls a function implicitly (it's an operator expression and the operator is overloaded, it is a new-expression and the allocation function is overloaded, or it is a full expression and the destructor of a temporary is called)), then the set is the set of that function. 3) If e is a throw-expression, the set is the exception that would be initialized by its operand, or the set of all types for the re-throwing throw-expression (with no operand) 4) If e is a dynamic_cast to a reference to a polymorphic type, the set consists of std::bad_cast 5) If e is a typeid applied to a polymorphic glvalue, the set consists of std::bad_typeid 6) If e is a new-expression with a non-constant size, the set consists of std::bad_array_new_length void f() throw(int); // f()'s set is "int" void g(); // g()'s set is the set of all types struct A { A(); }; // "new A"'s set is the set of all types struct B { B() noexcept; }; // "B()"'s set is empty struct D() { D() throw (double); }; // new D's set is the set of all types All implicitly-declared member functions (and inheriting constructors) have exception specifications, selected as follows: If the set of potential exceptions is the set of all types, the implicit exception specification is noexcept(false). Otherwise, If the set of potential exceptions is not empty, the implicit exception specification lists every type from the set Otherwise, the implicit exception specification is noexcept(true) and the function type is "noexcept function" struct A { A(int = (A(5), 0)) noexcept; A(const A&) throw(); A(A&&) throw(); ~A() throw(X); }; struct B { B() throw(); B(const B&) = default; // exception specification is "noexcept(true)" B(B&&, int = (throw Y(), 0)) throw(Y) noexcept; ~B() throw(Y); }; int n = 7; struct D : public A, public B { int * p = new (std::nothrow) intn; // D has the following implicitly-declared members: // D::D() throw(X, std::bad_array_new_length); // D::D(const D&) noexcept(true); // D::D(D&&) throw(Y); // D::~D() throw(X, Y); };

(since C++17)