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Why use apparently meaningless do-while and if-else statements in macros?
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The do ... while and if ... else are there to make it so that a
semicolon after your macro always means the same thing. Let's say you
had something like your second macro.
#define BAR(X) f(x); g(x)
Now if you were to use BAR(X); in an if ...
How can I check if a string is null or empty in PowerShell?
... null strings passed to a commandlet or function don't stay null. They get converted to empty strings. See the Microsoft Connect bug at connect.microsoft.com/PowerShell/feedback/details/861093/….
– JamieSee
Dec 11 '14 at 17:59
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Combine two ActiveRecord::Relation objects
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Relation objects can be converted to arrays. This negates being able to use any ActiveRecord methods on them afterwards, but I didn't need to. I did this:
name_relation = first_name_relation + last_name_relation
Ruby 1.9, rails 3.2
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How can I check whether an array is null / empty?
I have an int array which has no elements and I'm trying to check whether it's empty.
13 Answers
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Where is array's length property defined?
... method clone, which overrides the method of the same name in class Object and throws no checked exceptions. The return type of the clone method of an array type T[] is T[].
A clone of a multidimensional array is shallow, which is to say that it creates only a single new array. Subarrays are sh...
What are some uses of template template parameters?
... all specializations of H.
NOTE: I've been programming c++ for many years and have only needed this once. I find that it is a rarely needed feature (of course handy when you need it!).
I've been trying to think of good examples, and to be honest, most of the time this isn't necessary, but let's co...
What does Expression.Quote() do that Expression.Constant() can’t already do?
...e quote operator is an operator which induces closure semantics on its operand. Constants are just values.
Quotes and constants have different meanings and therefore have different representations in an expression tree. Having the same representation for two very different things is extremely confu...
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.
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Calculate the number of business days between two dates?
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I've had such a task before and I've got the solution.
I would avoid enumerating all days in between when it's avoidable, which is the case here. I don't even mention creating a bunch of DateTime instances, as I saw in one of the answers above. This is ...
How to randomly select rows in SQL?
... 2005. In my db, I have a table "customerNames" which has two columns "Id" and "Name" and approx. 1,000 results.
11 Answer...