exception specification
Lists the exceptions that a function might directly or indirectly throw.
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[edit] Syntax
throw( typeid, typeid, ...)
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[edit] Explanation
If a function is declared with type T
listed in its exception specification, the function may throw exceptions of that type or a type derived from it.
If the function throws an exception of the type not listed in its exception specification, the function std::unexpected is called. The default function calls std::terminate, but it may be replaced by a user-provided function (via std::set_unexpected) which may call std::terminate or throw an exception. If the exception thrown from std::unexpected is accepted by the exception specification, stack unwinding continues as usual. If it isn't, but std::bad_exception is allowed by the exception specification, std::bad_exception is thrown. Otherwise, std::terminate is called.
[edit] Example
class X {}; class Y {}; class Z : public X {}; class W {}; void f() throw(X, Y) { int n = 0; if (n) throw X(); // OK if (n) throw Z(); // also OK throw W(); // will call std::unexpected() }