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In which situations do we need to write the __autoreleasing ownership qualifier under ARC?
...ents that are passed by reference (id *) and are autoreleased on return.
All of this is very well explained in the ARC transition guide.
In your NSError example, the declaration means __strong, implicitly:
NSError * e = nil;
Will be transformed to:
NSError * __strong error = nil;
When you c...
How do you serialize a model instance in Django?
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You can easily use a list to wrap the required object and that's all what django serializers need to correctly serialize it, eg.:
from django.core import serializers
# assuming obj is a model instance
serialized_obj = serializers.serialize('json', [ obj, ])
...
How do I list the symbols in a .so file
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Note that readelf -Ws will show you all symbols, and nm -g shows only the externally visible symbols. This may be confusing if you are examining multiple symbol files and start interchanging your commands.
– Andrew B
May 2...
Loop backwards using indices in Python?
... This is better than the accepted answer since it doesn't actually allocate all the numbers in memory (in Python 3 the accepted answer wouldn't either), plus it's more obvious what is happening.
– Blixt
Mar 23 '12 at 13:52
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Makefile, header dependencies
...vided by the gnu preprocessor are a bit confusing. However, the removal of all directories from the build target with -MM is documented and not a bug [gpp]:
By default CPP takes the name of the main input file, deletes any
directory components and any file suffix such as ‘.c’, and appends ...
C# operator overload for `+=`?
...nguage has its own operators list, which are compiled in a special method calls, and CLR itself doesn't know anything about operators. So let's see what exactly stays behind the + and += operators.
See this simple code:
Decimal d = 10M;
d = d + 10M;
Console.WriteLine(d);
Let view the IL-code for...
How can you determine a point is between two other points on a line segment?
Let's say you have a two dimensional plane with 2 points (called a and b) on it represented by an x integer and a y integer for each point.
...
Is inline assembly language slower than native C++ code?
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Yes, most times.
First of all you start from wrong assumption that a low-level language (assembly in this case) will always produce faster code than high-level language (C++ and C in this case). It's not true. Is C code always faster than Java code? N...
How can I get the current screen orientation?
...lues ORIENTATION_PORTRAIT and ORIENTATION_LANDSCAPE. Is there a way to get all the four values from ActivityInfo? (That is LANDSCAPE_REVERSE and PORTRAIT_REVERSE as well)
– HRJ
May 4 '11 at 9:56
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Javascript equivalent of Python's zip function
..., unlike Python's version where the argument list is variadic. If you want all of these "features", see below. It takes just about 2 extra lines of code.
The following will mimic Python's zip behavior on edge cases where the arrays are not of equal size, silently pretending the longer parts of arra...