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What is the difference between quiet NaN and signaling NaN?
...unit (FPU) or library if floating-point is implemented in software. A signalling NaN will produce a signal, usually in the form of exception from the FPU. Whether the exception is thrown depends on the state of the FPU.
C++11 adds a few language controls over the floating-point environment and pr...
What does extern inline do?
...e, static inline, and extern inline constructs; most pre-C99 compiler generally follow its lead.
GNU89:
inline: the function may be inlined (it's just a hint though). An out-of-line version is always emitted and externally visible. Hence you can only have such an inline defined in one compilatio...
Saving an Object (Data persistence)
...ics.
cPickle (or _pickle) vs pickle
It's almost always preferable to actually use the cPickle module rather than pickle because the former is written in C and is much faster. There are some subtle differences between them, but in most situations they're equivalent and the C version will provide gr...
Forced naming of parameters in Python
...(10, forcenamed=20)
10 20
>>> foo(10, 20)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: foo() takes exactly 1 positional argument (2 given)
This can also be combined with **kwargs:
def foo(pos, *, forcenamed, **kwargs):
...
What is the difference between class and instance attributes?
...just look in each instance's __dict__ and the class's __dict__. It just usually doesn't matter very much whether immutable types are shared or not.
– abarnert
Oct 29 '14 at 22:58
1...
Is the list of Python reserved words and builtins available in a library?
...break', 'class', 'continue', 'def',
'del', 'elif', 'else', 'except', 'finally', 'for', 'from', 'global', 'if', 'import',
'in', 'is', 'lambda', 'nonlocal', 'not', 'or', 'pass', 'raise', 'return', 'try',
'while', 'with', 'yield']
If you want to include built-in names as well (Python 3), then c...
What are the mechanics of short string optimization in libc++?
...ver, I would like to know in more detail how it works in practice, specifically in the libc++ implementation:
2 Answers
...
Best way to use PHP to encrypt and decrypt passwords? [duplicate]
...ing. You should not rely on unauthenticated encryption for security, especially since the code as provided is vulnerable to padding oracle attacks.
See also:
https://stackoverflow.com/a/30189841/2224584
https://stackoverflow.com/a/30166085/2224584
https://stackoverflow.com/a/30159120/2224584
Al...
How do I check for C++11 support?
...t have (partial) compiler-level support versus a standard C++ library with all the C++11 changes.
So Boost's defines mentioned in another answer remain the only sane way to figure out if there is, for example, support for C++11 threads and other specific parts of the standard.
...
How can I open multiple files using “with open” in Python?
I want to change a couple of files at one time, iff I can write to all of them. I'm wondering if I somehow can combine the multiple open calls with the with statement:
...