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What is the advantage of GCC's __builtin_expect in if else statements?
...ipeline better, since a jump thrashes the already fetched instructions.
Before the jump is executed, the instructions below it (the bar case) are pushed to the pipeline. Since the foo case is unlikely, jumping too is unlikely, hence thrashing the pipeline is unlikely.
...
What does “mro()” do?
...: the class, its base, its base's base, and so on up to object (only works for new-style classes of course).
Now, with multiple inheritance...:
>>> class D(B, C): pass
...
>>> D.__mro__
(<class '__main__.D'>, <class '__main__.B'>, <class '__main__.C'>, <clas...
Difference between __str__ and __repr__?
...defaults tend to be fairly useful. However, in this case, having a default for __repr__ which would act like:
return "%s(%r)" % (self.__class__, self.__dict__)
would have been too dangerous (for example, too easy to get into infinite recursion if objects reference each other). So Python cops out....
How do I get the full path to a Perl script that is executing?
...eList; print Module::CoreList->first_release("File::Basename");'; echo. For File::Basename that was Perl 5.0.0, which was released in the late '90s—I think it's save to use by now.
– Drew Stephens
Apr 5 '16 at 12:18
...
Can “using” with more than one resource cause a resource leak?
...
No.
The compiler will generate a separate finally block for each variable.
The spec (§8.13) says:
When a resource-acquisition takes the form of a
local-variable-declaration, it is possible to acquire multiple
resources of a given type. A using statement of the form
usin...
Difference between len() and .__len__()?
...e even more added value beyond simple sanity checks and readability. By uniformly designing all of Python to work via calls to builtins and use of operators, never through calls to magic methods, programmers are spared from the burden of remembering which case is which. (Sometimes an error slips in...
Is gcc's __attribute__((packed)) / #pragma pack unsafe?
...n gcc would, I believe, be impractical. A general solution would require, for each attempt to dereference a pointer to any type with non-trivial alignment requirements either (a) proving at compile time that the pointer doesn't point to a misaligned member of a packed struct, or (b) generating bulk...
How can I tell gcc not to inline a function?
...e.
This function attribute prevents a
function from being considered for
inlining. If the function does not
have side-effects, there are
optimizations other than inlining that
causes function calls to be optimized
away, although the function call is
live. To keep such calls from be...
How to find the size of localStorage
...make use of HTML5's localStorage. I've read all about the size limitations for different browsers. However, I haven't seen anything on how to find out the current size of a localStorage instance. This question seems to indicate that JavaScript doesn't have a built in way of showing the size for a ...
Python name mangling
...g
def push(self, value):
self.storage.append(value)
This is for sure a controversial way of doing things. Python newbies just hate it and even some old Python guys despise this default - but it is the default anyway, so I really recommend you to follow it, even if you feel uncomfortab...