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What is this crazy C++11 syntax ==> struct : bar {} foo {};?
...stract UDT (User-Defined Type):
struct foo { virtual void f() = 0; }; // normal abstract type
foo obj;
// error: cannot declare variable 'obj' to be of abstract type 'foo'
Let's also recall that we can instantiate the UDT at the same time that we define it:
struct foo { foo() { cout << "!"...
django - query filter on manytomany is empty
In Django is there a way to filter on a manytomany field being empty or null.
2 Answers
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Calling static generic methods
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Or, as in my case: Foo.<E>createFoo(); Thank you :)
– fredoverflow
Mar 14 '11 at 11:37
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Why must we define both == and != in C#?
The C# compiler requires that whenever a custom type defines operator == , it must also define != (see here ).
13 Answe...
How to decide between MonoTouch and Objective-C? [closed]
...cal .Net event, the use of MonoTouch was 'touched' upon as an alternative for iPhone development. Being very comfortable in C# and .Net, it seems like an appealing option, despite some of the quirkiness of the Mono stack. However, since MonoTouch costs $400, I'm somewhat torn on if this is the way...
Reset the database (purge all), then seed a database
...es the database and includes your seeds.rb file.
http://guides.rubyonrails.org/migrations.html#resetting-the-database
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How to switch back to 'master' with git?
...d to checkout the branch:
git checkout master
See the Git cheat sheets for more information.
Edit: Please note that git does not manage empty directories, so you'll have to manage them yourself. If your directory is empty, just remove it directly.
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How do you determine which backend is being used by matplotlib?
Either interactively, such as from within an Ipython session, or from within a script, how can you determine which backend is being used by matplotlib?
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How do I convert a string to a number in PHP?
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You don't typically need to do this, since PHP will coerce the type for you in most circumstances. For situations where you do want to explicitly convert the type, cast it:
$num = "3.14";
$int = (int)$num;
$float = (float)$num;
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What does “coalgebra” mean in the context of programming?
.... They can also have "identities"—elements of τ that have special behavior with some of the functions.
The simplest example of this is the monoid. A monoid is any type τ with a function mappend ∷ (τ, τ) → τ and an identity mzero ∷ τ. Other examples include things like groups (which ar...