Make the capacity of this array at least the specified numElements, assuming the number of unique elements within this array does not increase. This method has no effect if the current capacity meets or exceeds the required capacity. The behavior is undefined unless false == isEmpty() || 0 == numElements. Note that the assumption of not increasing the number of unique elements implies the need for the narrow contract.
Declared in <bdlc_compactedarray.h>
void
reserveCapacity(std::size_t numElements);