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How to concatenate twice with the C preprocessor and expand a macro as in “arg ## _ ## MACRO”?
...then substituted into the replacement string:
EVALUATOR(mine, VARIABLE)
Now the macro EVALUATOR is discovered, and the arguments are isolated as 'mine' and 'VARIABLE'; the latter is then fully expanded to '3', and substituted into the replacement string:
PASTER(mine, 3)
The operation of this i...
How to pass the values from one activity to previous activity
.... Shared Preferences
Suppose you want to store username. So there will be now two thing a Key Username, Value Value.
How to store
// Create object of SharedPreferences.
SharedPreferences sharedPref = PreferenceManager.getDefaultSharedPreferences(this);
//now get Editor
SharedPreferences.Edito...
Add regression line equation and R^2 on graph
... parse = TRUE) +
geom_point()
p
@shabbychef Now it is possible to match the variables in the equation to those used for the axis-labels. To replace the x with say z and y with h one would use:
p <- ggplot(data = df, aes(x = x, y = y)) +
geom_smooth(method = "lm"...
What are the security risks of setting Access-Control-Allow-Origin?
...w-Origin to * in order to be able to make cross-subdomain ajax calls.
Now I can't help but feel that I'm putting my environment to security risks.
Please help me if I'm doing it wrong.
...
Why is React's concept of Virtual DOM said to be more performant than dirty model checking?
... might find in knockout or other MVVM style libraries. Essentially, React knows when to re-render the scene because it is able to observe when this data changes. Dirty checking is slower than observables because you must poll the data at a regular interval and check all of the values in the data str...
How to get the original value of an attribute in Rails
...flow.com/a/50973808/9359123
Appending _was is deprecated in rails 5.1, now you should append _before_last_save
Something like:
before_save object
do_something_with object.name_before_last_save
end
Will return the name value before your last save at database (works for save and create)
The...
Amazon SimpleDB vs Amazon DynamoDB
...'s Summary suggests DynamoDB to be a good fit for applications of any size now accordingly:
Amazon DynamoDB is designed to maintain predictably high performance
and to be highly cost efficient for workloads of any scale, from the
smallest to the largest internet-scale applications.
...
How to remove all debug logging calls before building the release version of an Android app?
...See also the examples in the ProGuard manual.
Update (4.5 years later): Nowadays I used Timber for Android logging.
Not only is it a bit nicer than the default Log implementation — the log tag is set automatically, and it's easy to log formatted strings and exceptions — but you can also spec...
Should I pass an std::function by const-reference?
...id> run_in_ui_thread( std::function<void()> const& ) // (B)
Now, we are likely to use these as follows:
run_in_ui_thread( [=]{
// code goes here
} ).wait();
which will create an anonymous closure (a lambda), construct a std::function out of it, pass it to the run_in_ui_thread fun...
How to encode the filename parameter of Content-Disposition header in HTTP?
...
I know this is an old post but it is still very relevant. I have found that modern browsers support rfc5987, which allows utf-8 encoding, percentage encoded (url-encoded). Then Naïve file.txt becomes:
Content-Disposition: atta...