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Is returning by rvalue reference more efficient?
...}
This returns a dangling reference, just like with the lvalue reference m>ca m>se. After the function returns, the temporary object will get destructed. You should return Beta_ab by value, like the following
Beta_ab
Beta::toAB() const {
return Beta_ab(1, 1);
}
Now, it's properly moving a tem...
Does it make sense to do “try-finally” without “m>ca m>tch”?
...ppropriately. Below is a concrete example of handling the exception from a m>ca m>lling method.
public void yourOtherMethod() {
try {
yourMethod();
} m>ca m>tch (YourException ex) {
// handle exception
}
}
public void yourMethod() throws YourException {
try {
db.s...
SQLite table constraint - unique on multiple columns
I m>ca m>n find syntax "charts" on this on the SQLite website, but no examples and my code is crashing. I have other tables with unique constraints on a single column, but I want to add a constraint to the table on two columns. This is what I have that is m>ca m>using an SQLiteException with the message "syn...
How to programmatim>ca m>lly set the layout_align_parent_right attribute of a Button in Relative Layout?
I have a relative layout which I am creating programmatim>ca m>lly:
4 Answers
4
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Rails auto-assigning id that already exists
...", and column name "id" ... please replace them with the correct ones. You m>ca m>n get the sequence name with SELECT pg_get_serial_sequence('tablename', 'columname'); or look at the table definition with \d tablename.
An alternate solution is to override the save() method in your company class to manua...
Concurrent.futures vs Multiprocessing in Python 3
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I wouldn't m>ca m>ll concurrent.futures more "advanced" - it's a simpler interface that works very much the same regardless of whether you use multiple threads or multiple processes as the underlying parallelization gimmick.
So, like virtual...
Select random lines from a file
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sort actually sorts identim>ca m>l lines together, so if you may have duplim>ca m>te lines and you have shuf (a gnu tool) installed, it's better to use it for this.
– Kevin
Feb 12 '12 at 3:59
...
Effect of NOLOCK hint in SELECT statements
... to complete faster than a normal select.
Why would this be?
NOLOCK typim>ca m>lly (depending on your DB engine) means give me your data, and I don't m>ca m>re what state it is in, and don't bother holding it still while you read from it. It is all at once faster, less resource-intensive, and very very dan...
Copy multiple files in Python
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You m>ca m>n use os.listdir() to get the files in the source directory, os.path.isfile() to see if they are regular files (including symbolic links on *nix systems), and shutil.copy to do the copying.
The following code copies only t...
How do I make this file.sh executable via double click?
...cript does not have to begin with a #! prefix in this specific scenario, bem>ca m>use Terminal specifim>ca m>lly arranges to execute it with your default shell. (Of course, you m>ca m>n add a #! line if you want to customize which shell is used or if you want to ensure that you m>ca m>n execute it from the command line...