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Does Python support short-circuiting?
...ions with length 0 (so on top of what you listed, b'' [Py3], u'' [Py2] and set()/frozenset() are all built-ins that evaluate as falsy), but user-defined/third-party types can define their own (with __bool__ [Py3]/__nonzero__ [Py2] directly, or indirectly by defining __len__).
–...
Is optimisation level -O3 dangerous in g++?
...w has the ability to put attributes at functions that control optimization settings just for these functions, so when you find you have a problem with -O3 in one function (or want to try out special flags for just that function), you don't need to compile the whole file or even whole project with O2...
Show the progress of a Python multiprocessing pool imap_unordered call?
I have a script that's successfully doing a multiprocessing Pool set of tasks with a imap_unordered() call:
9 Answers
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Specifying column name in a “references” migration
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Initial Definition:
If you are defining your Post model table, you can set references, index and foreign_key in one line:
t.references :author, index: true, foreign_key: { to_table: :users }
Update Existing:
If you are adding references to an existing table, you can do this:
add_reference...
Best practices for reducing Garbage Collector activity in Javascript
...in future iterations. Avoid allocation just to return function results by setting variables in an enclosing scope instead. You will have to consider each object type in its own context to find the best strategy. If you need help with specifics, post an edit describing details of the challenge you...
What does the question mark in Java generics' type parameter mean?
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so what does public Set<Class<?>> getClasses() mean? What's the difference with Set<Class>? I'm looking at javax.ws.rs.core.Application.
– vault
Apr 23 '15 at 14:38
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Why doesn't JavaScript have a last method? [closed]
...ue,
get: function() {
return this[this.length - 1];
},
set: undefined
});
var arr = [1, 2, 5];
arr.last; // 5
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bundle install returns “Could not locate Gemfile”
...ying a Gemfile into a docker container, I couldnt find a .bundle and I had set my WOKRDIR but it didnt seem to catch it for bundle install, this did the trick!
– ConstantineK
Mar 22 '16 at 3:15
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presentViewController and displaying navigation bar
...ally present a navigation controller modally with its root view controller set as the view controller you want:
MyViewController *myViewController = [[MyViewController alloc] initWithNibName:nil bundle:nil];
UINavigationController *navigationController =
[[UINavigationController alloc] initWit...
Android device does not show up in adb list [closed]
... Can confirm that this is critical! On Android 5.0, go to Settings -> Storage -> menu -> USB computer connection and make sure 'Media device (MTP)' is disabled. When it's disabled 'adb devices' lists the device, when enabled not. Tried with both Nexus 4 and Nexus 5.
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