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In C#, why is String a reference type that behaves like a value type?
... it's never desirable to check the references, since sometimes new String("foo"); and another new String("foo") can evaluate in the same reference, which kind of is not what you would expect a new operator to do. (Or can you tell me a case where I would want to compare the references?)
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Is it possible to make a type only movable and not copyable?
...of a value is a byte copy:
let x: T = ...;
let y: T = x; // byte copy
fn foo(z: T) -> T {
return z // byte copy
}
foo(y) // byte copy
They are byte copies whether or not T moves or is "implicitly copyable". (To be clear, they aren't necessarily literally byte-by-byte copies at run-time: ...
Difference between len() and .__len__()?
...h case is which. (Sometimes an error slips in: until 2.5, you had to call foo.next() -- in 2.6, while that still works for backwards compatibility, you should call next(foo), and in 3.*, the magic method is correctly named __next__ instead of the "oops-ey" next!-).
So the general rule should be to...
How can I dynamically create derived classes from a base class
...g (anything?) to fill the gap would suffice. For example, obj = SubClass('foo') runs without error.
– DaveL17
Oct 3 '17 at 12:16
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Calling Objective-C method from C++ member function?
...++ file be treated as Objective-C++. You can do this in xcode by renaming foo.cpp to foo.mm (.mm is the obj-c++ extension). Then as others have said standard obj-c messaging syntax will work.
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How to change a module variable from another module?
... actually derived from __init__.py. It does not change the value of a that foobar sees because foobar lives in the actual file bar.py. You could set bar.bar.a if you wanted to change that.
This is one of the dangers of using the from foo import bar form of the import statement: it splits bar into t...
Difference between / and /* in servlet mapping url pattern
...ill be selected only after servlet mappings which are exact matches (like /foo/bar) and those which are path mappings longer than /* (like /foo/*). Note that the empty string mapping is an exact match for the context root (http://host:port/context/).
See Chapter 12 of the Java Servlet Specificatio...
What is the difference between URI, URL and URN? [duplicate]
...to:user@example.com
file:///home/user/file.txt
http://example.com/resource?foo=bar#fragment
/other/link.html (A relative URL, only useful in the context of another URL)
URLs always start with a protocol (http) and usually contain information such as the network host name (example.com) and often a ...
What is a monad?
...ay<U> and return an Array<U>.
Generalized, a monad is any type Foo<Bar> which has a "bind" method which takes a function argument of type Bar => Foo<Baz> and returns a Foo<Baz>.
This answers what monads are. The rest of this answer will try to explain through example...
Relationship between SciPy and NumPy
...s in its own namespace. In other words, if there's a function named numpy.foo , there's almost certainly a scipy.foo . Most of the time, the two appear to be exactly the same, oftentimes even pointing to the same function object.
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