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Is there a “do … while” loop in Ruby?
...egin...end is quite powerful. The following is a common idiom to memoize a one-liner method with no params:
def expensive
@expensive ||= 2 + 2
end
Here is an ugly, but quick way to memoize something more complex:
def expensive
@expensive ||=
begin
n = 99
buf = ""
begin
...
PostgreSQL function for last inserted ID
...ue. The problem can even happen with CURRVAL, if the extra insertions are done intto the same persons table (this is much less usual, but the risk still exists).
Option 3: INSERT with RETURNING
INSERT INTO persons (lastname,firstname) VALUES ('Smith', 'John') RETURNING id;
This is the most c...
Run certain code every n seconds [duplicate]
...t__(self, interval, function, *args, **kwargs):
self._timer = None
self.interval = interval
self.function = function
self.args = args
self.kwargs = kwargs
self.is_running = False
self.start()
def _run(self):
self....
What is DOM Event delegation?
Can anyone please explain event delegation in JavaScript and how is it useful?
11 Answers
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How much is the overhead of smart pointers compared to normal pointers in C++?
...rements/decrements are atomic, thus adding some more overhead.
Note that none of them has time overhead in dereferencing (in getting the reference to owned object), while this operation seems to be the most common for pointers.
To sum up, there is some overhead, but it shouldn't make the code slow...
When using Spring Security, what is the proper way to obtain current username (i.e. SecurityContext)
...u could inject that. In fact, I even opened a Jira issue to that effect.
One last thing - I've just substantially changed the answer I had here before. Check the history if you're curious but, as a coworker pointed out to me, my previous answer would not work in a multi-threaded environment. The...
What is the difference between integration testing and functional testing? [closed]
...
Integration testing is when you test more than one component and how they function together. For instance how another system interacts with your system or the database interacts with your data abstraction layer. Usually this requires an fully installed system, although in...
How to copy yanked text to VI command prompt
...;ctl-w>
This eschews yanking to paste into the command line; instead, one pastes the word under one's cursor directly onto the command line. E.g.:
:%s/<ctl-r><ctl-w>/foo/g
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What is the size of column of int(11) in mysql in bytes?
...its of space with 2^(31) = 2147483648 max value and -2147483648min value. One bit is for sign.
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What is meant by Scala's path-dependent types?
..., giving a sort of type safety that is dependent on values and not types alone.
This might sound like dependent types, but it is more limited. For example, the type of occupied is dependent on the value of Board. Above, the last line doesn't work because the type of c2 is b2.Coordinate, while occup...