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Rake just one migration
...n a single migration that changed and needed to be re-run independently of all other migrations. Fire up the console and do this:
>> require 'db/migrate/your_migrations.rb'
=> ["YourMigrations"]
>> YourMigrations.up
=> etc... as the migration runs
>> YourMigration.down
Mor...
What is the difference between a definition and a declaration?
...// extern can be omitted for function declarations
class foo; // no extern allowed for type declarations
A definition actually instantiates/implements this identifier. It's what the linker needs in order to link references to those entities. These are definitions corresponding to the above declara...
Is it safe to resolve a promise multiple times?
... rejected), that is it for a defered object - it is done.
If you should call then(...) on it's promise again, you should immediately get the (first) resolved/rejected result.
Additional calls to resolve() will not (should not?) have any effect. Not sure what happens if you attempt to reject a de...
MySQL Cannot drop index needed in a foreign key constraint
...
You have to drop the foreign key. Foreign keys in MySQL automatically create an index on the table (There was a SO Question on the topic).
ALTER TABLE mytable DROP FOREIGN KEY mytable_ibfk_1 ;
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How to install the Raspberry Pi cross compiler on my Linux host machine?
...make example.
– pqvst
Oct 10 '13 at 15:03
1
This works well for simple projects, but I can't cros...
How can I listen for a click-and-hold in jQuery?
...tartTrigger(e) {
var $elem = $(this);
$elem.data('mouseheld_timeout', setTimeout(function() {
$elem.trigger('mouseheld');
}, e.data));
}
function stopTrigger() {
var $elem = $(this);
clearTimeout($elem.data('mouseheld_timeout'));
}
...
Download a file by jQuery.Ajax
...ence is when a file download occurs.
I created jQuery File Download which allows for an "Ajax like" experience with file downloads complete with OnSuccess and OnFailure callbacks to provide for a better user experience. Take a look at my blog post on the common problem that the plugin solves and so...
What is the best way to concatenate two vectors?
...
AB.reserve( A.size() + B.size() ); // preallocate memory
AB.insert( AB.end(), A.begin(), A.end() );
AB.insert( AB.end(), B.begin(), B.end() );
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Why the switch statement cannot be applied on strings?
...
The reason why has to do with the type system. C/C++ doesn't really support strings as a type. It does support the idea of a constant char array but it doesn't really fully understand the notion of a string.
In order to generate the code for a switch statement the compiler must under...
Disable developer mode extensions pop up in Chrome
... to chrome://extensions, check Developer mode and click Pack extension
Install the extension by dragging and dropping the .crx file into the chrome://extensions page.
You'll get an "Unsupported extensions disabled" popup if you try restarting Chrome at this point.
Then for Windows 7 or Windows 8:...