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#ifdef replacement in the Swift language

... After i set the custom flag -DLOCAL, on my #if LOCAl #else #endif, it falls into the #else section. I duplicated the original target AppTarget and rename it to AppTargetLocal & set its custom flag. – Perwyl Liu Jul 20 '16 at 6:48 ...
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Why declare a struct that only contains an array in C?

... It allows you to pass the array to a function by value, or get it returned by value from a function. Structs can be passed by value, unlike arrays which decay to a pointer in these contexts. ...
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rails - Devise - Handling - devise_error_messages

...hould help you get started. :) Another update The resource object is actually the model that is being used by devise (go figure). resource.class #=> User resource.errors.class #=> ActiveModel::Error It also appears to be defined in a higher scope (probably coming from the contro...
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Difference between timestamps with/without time zone in PostgreSQL

...d '2011-07-01 06:30:30+05' is ignored but i'm able to do insert into test_table (date) values ('2018-03-24T00:00:00-05:00'::timestamptz); and it will convert it to utc correctly. where date is timestamp without timezone. I'm trying to understand what the main value of timestamp with timezone is an...
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Is there a standard sign function (signum, sgn) in C/C++?

...T val) { return (T(0) < val) - (val < T(0)); } Benefits: Actually implements signum (-1, 0, or 1). Implementations here using copysign only return -1 or 1, which is not signum. Also, some implementations here are returning a float (or T) rather than an int, which seems wasteful. Works ...
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Reflection - get attribute name and value on property

I have a class, lets call it Book with a property called Name. With that property, I have an attribute associated with it. ...
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What are type lambdas in Scala and what are their benefits?

...ction of Either[A, B]. The monad typeclass looks like this: trait Monad[M[_]] { def point[A](a: A): M[A] def bind[A, B](m: M[A])(f: A => M[B]): M[B] } Now, Either is a type constructor of two arguments, but to implement Monad, you need to give it a type constructor of one argument. The sol...
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What happens to a detached thread when main() exits?

..._local) variables of other threads nor static objects. This appears to be allowed to allow thread managers as static objects (note in [basic.start.term]/4 says as much, thanks to @dyp for the pointer). Problems arise when the destruction of static objects has finished, because then execution enter...
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What is the list of valid @SuppressWarnings warning names in Java?

...pends on your IDE or compiler. Here is a list for Eclipse Galileo: all to suppress all warnings boxing to suppress warnings relative to boxing/unboxing operations cast to suppress warnings relative to cast operations dep-ann to suppress warnings relative to deprecated annotation depr...
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How to read a large file - line by line?

... The for line in f treats the file object f as an iterable, which automatically uses buffered I/O and memory management so you don't have to worry about large files. There should be one -- and preferably only one -- obvious way to do it. ...