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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...
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 is normalized UTF-8 all about?
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Compatibility Normalization
Unicode also includes many characters that really do not belong, but were used in legacy character sets. Unicode added these to allow text in those character sets to be processed as Unicode, and then be converted back without loss.
Compatibility normalization converts t...
Create code first, many to many, with additional fields in association table
...join table. In a many-to-many relationship EF manages the join table internally and hidden. It's a table without an Entity class in your model. To work with such a join table with additional properties you will have to create actually two one-to-many relationships. It could look like this:
public c...
Maven fails to find local artifact
Occasionally maven complains that a particular dependency, which is built and packaged locally, cannot be found in the local repository while building another project that has it as a dependency. We get an error like:
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case-insensitive list sorting, without lowercasing the result?
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In Python 3.3+ there is the str.casefold method that's specifically designed for caseless matching:
sorted_list = sorted(unsorted_list, key=str.casefold)
In Python 2 use lower():
sorted_list = sorted(unsorted_list, key=lambda s: s.lower())
It works for both normal and unicode strin...
Using std Namespace
...efined vector.
I am always against using using namespace std;. It imports all sorts of names into the global namespace and can cause all sorts of non-obvious ambiguities.
Here are some common identifiers that are in the std namespace: count, sort, find, equal, reverse. Having a local variable call...
How to create a new object instance from a Type
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Glad to have finally found this, but second call is not exactly right, missing a quote and parms reversed, should be: ObjectType instance = (ObjectType)Activator.CreateInstance("MyAssembly","MyNamespace.ObjectType");
– ...
How to change collation of database, table, column?
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You need to either convert each table individually:
ALTER TABLE mytable CONVERT TO CHARACTER SET utf8mb4
(this will convert the columns just as well), or export the database with latin1 and import it back with utf8mb4.
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Does Python have a ternary conditional operator?
...s ignored, or else when b is evaluated and returned but a is ignored.
This allows short-circuiting because when condition is true only a is evaluated and b is not evaluated at all, but when condition is false only b is evaluated and a is not evaluated at all.
For example:
>>> 'true' if True...