BloombergLP::bdlc::operator‐

Return the number of elements between the specified lhs and rhs as a signed value. The behavior is undefined unless lhs and rhs reference the same array. Note that the return value is positive when a positive number of rhs++ invocations would result in lhs == rhs, and negative when a positive number of rhs‐‐ invocations would result in lhs == rhs.