c++ - understanding use_count with shared_ptr - Stack Overflow
Aug 6, 2015 · Why is use_count in the second statement printing 0 ? I read that the definition of use_count is: Returns the number of shared_ptr objects that share ownership over the same …
c++ - shared_ptr and use_count - Stack Overflow
Aug 12, 2012 · The postcondition that use count is 1 holds even if p is 0; invoking delete on a pointer that has a value of 0 is harmless. As you can see, it releases the last construct if you …
How does std::weak_ptr store its "use_count" information?
Sep 26, 2022 · So (1) If weak_ptr doesn't hold an integer pointer to shared_ptr's use_count, then , how does it know the use_count () should change from 1 to 0 when I called sp.reset(new …
Is it possible to specify condition in Count ()? - Stack Overflow
Is it possible to specify a condition in Count()? I would like to count only the rows that have, for example, "Manager" in the Position column. I want to do it in the count statement, not using WH...
How to use count and group by at the same select statement
Apr 27, 2010 · I think they mean if you put COUNT (DISTINCT town) in the WHERE clause. That is because it is an aggregate function and needs to be provided in the HAVING clause. This …
c# - List<T> Any or Count? - Stack Overflow
Better to use Any () on Enumerables and Count on Collections. If someone feels writing ' (somecollection.Count > 0)' will confuse or cause readability issues, better write it as an …
sql - Selecting COUNT (*) with DISTINCT - Stack Overflow
In SQL Server 2005 I have a table cm_production that lists all the code that's been put into production. The table has a ticket_number, program_type, program_name and push_number …
c# - Count property vs Count () method? - Stack Overflow
Nov 1, 2011 · Decompiling the source for the Count() extension method reveals that it tests whether the object is an ICollection (generic or otherwise) and if so simply returns the …
Which method performs better: .Any () vs .Count () > 0?
Better to use Any () on Enumerables and Count on Collections. If someone feels writing ' (somecollection.Count > 0)' will confuse or cause readability issues, better write it as an …
c# - When should I use .Count () and .Count in the context of an ...
May 18, 2012 · 1 Count retrieves the property from a List (already calculated). Count () is an aggregation, like Sum (), Average (), etc. What it does is to count the items in the enumerable …