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When to use std::forward to forward arguments?
...&& ...args)
{
g(std::forward<Args>(args)...);
}
That's because of the reference collapsing rules: If T = U&, then T&& = U&, but if T = U&&, then T&& = U&&, so you always end up with the correct type inside the function body. Finally, you need...
What is RSS and VSZ in Linux memory management
...SS and VSZ in Linux memory management? In a multithreaded environment how can both of these can be managed and tracked?
5 ...
Is “inline” without “static” or “extern” ever useful in C99?
...question, I think:
What does extern inline do?
The idea is that "inline" can be used in a header file, and then "extern inline" in a .c file. "extern inline" is just how you instruct the compiler which object file should contain the (externally visible) generated code.
[update, to elaborate]
I ...
Reference: Comparing PHP's print and echo
...thy values and this derives from PHP's Perl legacy.
But, if this is the case, then one may wonder why echo take multiple arguments whereas print can only handle one. For this answer we need to turn to the parser, specifically the file zend_language_parser.y. You will note that echo has the flex...
Multiprocessing - Pipe vs Queue
...
A Pipe() can only have two endpoints.
A Queue() can have multiple producers and consumers.
When to use them
If you need more than two points to communicate, use a Queue().
If you need absolute performance, a Pipe() is much faster ...
What GRANT USAGE ON SCHEMA exactly do?
...table, but not the right to see it in the schema that contains it then you can't access the table.
The rights tests are done in order:
Do you have `USAGE` on the schema?
No: Reject access.
Yes: Do you also have the appropriate rights on the table?
No: Reject access.
...
How exactly do Django content types work?
...orseen ways later down the road?" The reason why we ask this question is because this is what the Content Types framework does best: it creates generic relations between models. Blah blah, let's dive into some code and see what I mean.
# ourapp.models
from django.conf import settings
from django.db...
Different types of thread-safe Sets in Java
...
1) The CopyOnWriteArraySet is a quite simple implementation - it basically has a list of elements in an array, and when changing the list, it copies the array. Iterations and other accesses which are running at this time continue with the old array, avoiding necessity of synchronization betwee...
Ignoring time zones altogether in Rails and PostgreSQL
...e date/time family, literally. It has typispreferred set in pg_type, which can be relevant:
Generating time series between two dates in PostgreSQL
Internal storage and epoch
Internally, timestamps occupy 8 bytes of storage on disk and in RAM. It is an integer value representing the count of micros...
std::vector versus std::array in C++
...
std::vector is a template class that encapsulate a dynamic array1, stored in the heap, that grows and shrinks automatically if elements are added or removed. It provides all the hooks (begin(), end(), iterators, etc) that make it work fine with the rest of the STL...