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DCL54-CPP-EX1: A placement deallocation function may be elided for a corresponding placement allocation function, but only if the object placement allocation and object construction are guaranteed to be noexcept(true). Because placement deallocation functions are automatically invoked when some part of the object initialization throws terminates by throwing an exception, it is safe to elide the placement deallocation function when exceptions cannot be thrown. For instance, some vendors implement compiler flags disabling exception support (such as -fno-cxx-exceptions in Clang and /EHs-c- in Microsoft Visual Studio), which has implementation-defined behavior when an exception is thrown but generally results in program termination similar to calling abort().
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