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In this noncompliant code example, an exception of type S is thrown from f(). However, because S has a std::string data member, and the copy constructor for std::string is not declared noexcept(true), the implicitly defined copy constructor for S is also not declared to be noexcept(true). In low-memory situations, the copy constructor for std::string may be unable to allocate sufficient memory to complete the copy operation, resulting in a std::bad_alloc exception being thrown.
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