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Is it better to use std::memcpy() or std::copy() in terms to performance?

... of std::copy over memcpy: 2.99% My compiler is gcc 4.6.3 on Fedora 16 x86_64. My optimization flags are -Ofast -march=native -funsafe-loop-optimizations. Code for my SHA-2 implementations. I decided to run a test on my MD5 implementation as well. The results were much less stable, so I decided t...
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What are valid values for the id attribute in HTML?

...wed by any number of letters, digits ([0-9]), hyphens ("-"), underscores ("_"), colons (":"), and periods ("."). HTML 5 is even more permissive, saying only that an id must contain at least one character and may not contain any space characters. The id attribute is case sensitive in XHTML. As a ...
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When should you use constexpr capability in C++11?

...lues over and over? int func (int n) { static std::map<int, int> _cached; if (_cached.find (n) == _cached.end ()) _cached[n] = n > 0 ? n + func (n-1) : n; return _cached[n]; } The result By introducing your silly optimization, you just broke every usage of your function th...
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What is :: (double colon) in Python when subscripting sequences?

...n custom classes to make it do whatever you want class C(object): def __getitem__(self, k): return k # Single argument is passed directly. assert C()[0] == 0 # Multiple indices generate a tuple. assert C()[0, 1] == (0, 1) # Slice notation generates a slice object. assert C()[1:2:3] =...
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JSTL in JSF2 Facelets… makes sense?

...:forEach items="#{bean.items}" var="item"> <h:outputText id="item_#{item.id}" value="#{item.value}" /> </c:forEach> ...creates during view build time three separate <h:outputText> components in the JSF component tree, roughly represented like this: <h:outputText id="it...
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Dynamic cell width of UICollectionView depending on label width

...ered Apr 17 '14 at 14:07 Basheer_CADBasheer_CAD 4,6982121 silver badges3535 bronze badges ...
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How do I check in JavaScript if a value exists at a certain array index?

...his answer: stackoverflow.com/a/39171620/3120446 – dx_over_dt Jul 9 '19 at 20:19  |  show 9 more comments ...
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Why do assignment statements return a value?

... to be careful and draw your line for "simple" low for readability: return _myBackingField ?? (_myBackingField = CalculateBackingField()); A lot less chaff than checking for null and assigning. – Tom Mayfield Sep 27 '10 at 22:02 ...
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What's the simplest way to subtract a month from a date in Python?

...with param month doesn't work but months works In [23]: created_datetime__lt - relativedelta(months=1) Out[23]: datetime.datetime(2016, 11, 29, 0, 0, tzinfo=<StaticTzInfo 'Etc/GMT-8'>) In [24]: created_datetime__lt - relativedelta(month=1) Out[24]: datetime.datetime(2016, 1, 29,...
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Putting git hooks into repository

...sh if [ -x $0.local ]; then $0.local "$@" || exit $? fi if [ -x tracked_hooks/$(basename $0) ]; then tracked_hooks/$(basename $0) "$@" || exit $? fi The installation script would move all pre-existing hooks to the side (append .local to their names), and symlink all known hook names to the...