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C++ Language/Objects/Constructors/PlacementNew

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C++ Language
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  13. Obsolete Features

C++'s new operator allocates memory, and then executes some constructor within that memory. Low-level software might already have some memory pre-allocated for a new object, only wanting to run its constructor. To do so, call a "placement new" as CRType* poVar = new (preallocation) CRType;.

Additional information about placement new

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