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C default arguments
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Not really. The only way would be to write a varargs function and manually fill in default values for arguments which the caller doesn't pass.
share
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Python - Create a list with initial capacity
...bject %d" % ( i, )
result.append(message)
return result
def doAllocate( size=10000 ):
result=size*[None]
for i in range(size):
message= "some unique object %d" % ( i, )
result[i]= message
return result
Results. (evaluate each function 144 times and average ...
How to add property to a class dynamically?
...ing on. Better late than never.
You can add a property to a class dynamically. But that's the catch: you have to add it to the class.
>>> class Foo(object):
... pass
...
>>> foo = Foo()
>>> foo.a = 3
>>> Foo.b = property(lambda self: self.a + 1)
>>&...
Python: Is it bad form to raise exceptions within __init__?
...t have been designed with exception safety in mind, the destructor is not called if an exception is thrown in the constructor of an object (meaning that the initialization of the object is incomplete). This is often not the case in scripting languages, such as Python. For example, the following code...
How do I convert between big-endian and little-endian values in C++?
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If you're using Visual C++ do the following: You include intrin.h and call the following functions:
For 16 bit numbers:
unsigned short _byteswap_ushort(unsigned short value);
For 32 bit numbers:
unsigned long _byteswap_ulong(unsigned long value);
For 64 bit numbers:
unsigned __int64 _byt...
Ignore .pyc files in git repository
...t to to do it beforehand, if you just add the line to the .gitignore file, all previously committed .pyc files will still be tracked, so you'll need to remove them from the repository.
If you are on a Linux system (or "parents&sons" like a MacOSX), you can quickly do it with just this one line ...
What's the difference between using CGFloat and float?
I tend to use CGFloat all over the place, but I wonder if I get a senseless "performance hit" with this. CGFloat seems to be something "heavier" than float, right? At which points should I use CGFloat, and what makes really the difference?
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How to track down a “double free or corruption” error
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If you're using glibc, you can set the MALLOC_CHECK_ environment variable to 2, this will cause glibc to use an error tolerant version of malloc, which will cause your program to abort at the point where the double free is done.
You can set this from gdb by using ...
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...
Calling a class function inside of __init__
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Call the function in this way:
self.parse_file()
You also need to define your parse_file() function like this:
def parse_file(self):
The parse_file method has to be bound to an object upon calling it (because it's not a ...