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What is the curiously recurring template pattern (CRTP)?
... curiously recurring, isn't it? :)
Now, what does this give you? This actually gives the X template the ability to be a base class for its specializations.
For example, you could make a generic singleton class (simplified version) like this
template <class ActualClass>
class Singleton
{
...
Why does comparing strings using either '==' or 'is' sometimes produce a different result?
...l reasons: it is
inherently O(n) in the length of the
strings; it typically requires reads
from several regions of memory, which
take time; and the reads fills up the
processor cache, meaning there is less
cache available for other needs. With
interned strings, a simple object
identi...
Why do loggers recommend using a logger per class?
...ogger.DebugFormat("File not found: {0}", _filename); // Logger determines caller
-- or --
Logger.DebugFormat(this, "File not found: {0}", _filename); // Pass in the caller
Using the second example, the Logger would need to build a stack trace to see who was calling it or your code would always h...
Check if string ends with one of the strings from a list
...avi']
file_name = 'test.mp3'
if "." in file_name and file_name[file_name.rindex("."):] in extensions:
print(True)
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How can I see the raw SQL queries Django is running?
...t the output of the query is not valid SQL, because:
"Django never actually interpolates the parameters: it sends the query and the parameters separately to the database adapter, which performs the appropriate operations."
From Django bug report #17741.
Because of that, you should not send qu...
Is the practice of returning a C++ reference variable evil?
...
In general, returning a reference is perfectly normal and happens all the time.
If you mean:
int& getInt() {
int i;
return i; // DON'T DO THIS.
}
That is all sorts of evil. The stack-allocated i will go away and you are referring to nothing. This is also evil:
int& get...
Reliable method to get machine's MAC address in C#
...work across OS. Any ideas? I have been scraping the output of "ipconfig /all" but this is terribly unreliable as the output format differs on every machine.
...
What really happens in a try { return x; } finally { x = null; } statement?
...L level you can't return from inside an exception-handled block. It essentially stores it in a variable and returns afterwards
i.e. similar to:
int tmp;
try {
tmp = ...
} finally {
...
}
return tmp;
for example (using reflector):
static int Test() {
try {
return SomeNumber();
...
Too many 'if' statements?
...
You don't need the assert, Java will throw an IndexOutOfBoundsException anyway if one or more indices are out of bounds.
– JAB
Mar 19 '14 at 11:55
43
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How to convert currentTimeMillis to a date in Java?
...
Calendar objects are generally considered quite large, so should be avoided when possible. A Date object is going to be better assuming it has the functionality you need. "Date date=new Date(millis);" provided in the other answer by user AVD is going ...