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What are the differences between a pointer variable and a reference variable in C++?
...ontain nullptr.
int *p = nullptr;
int &r = nullptr; <--- compiling error
int &r = *p; <--- likely no compiling error, especially if the nullptr is hidden behind a function call, yet it refers to a non-existent int at address 0
Pointers can iterate over an array; you can use ++ to go...
Is it possible for a unit test to assert that a method calls sys.exit()
...
+1, as for checking error code it's far simpler to do just: self.assertRaisesRegex( SystemExit, '^2$', testMethod ) Less code, readable enough.
– Marek Lewandowski
Apr 11 '15 at 23:29
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Full examples of using pySerial package [closed]
...
I received an error serial.serialutil.SerialException: Port is already open when running this code. I'm not certain on this but I believe the serial port is automatically opened when it is explicitly defined as you have done with ser. Afte...
Failed to load JavaHL Library
After updating to Snow Lion I started receiving these errors in Flash Builder / Eclipse when trying to use SVN:
11 Answers...
How to convert a table to a data frame
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as.data.frame.matrix(table(x)) gives me Error in seq_len(ncols) : argument must be coercible to non-negative integer, while as.data.frame(table(x)) works, where x is just a numeric vector c(1,2,...)
– PatrickT
Oct 21 '17 at...
How do I use a file grep comparison inside a bash if/else statement?
...grep:
Exit status is 0 if any line was selected, 1 otherwise;
if any error occurs and -q was not given, the exit status is 2.
if grep --quiet MYSQL_ROLE=master /etc/aws/hosts.conf; then
echo exists
else
echo not found
fi
You may want to use a more specific regex, such as ^MYSQL_ROLE=ma...
vim “modifiable” is off
...his new file i created, i got the Cannot make changes, 'Modifiable' is off error and...
2) after running :set modifiable and trying to save, i would get an e382 error of 'cannot write, buftype is set. so i couldn't save.
After pouring throuch scads of useless cryptic documentation i figured out ...
Unable to resolve host “”; No address associated with hostname [closed]
In my Android application for reading RSS links, I am getting this error:
17 Answers
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Add Foreign Key to existing table
... Do not just run "SET FOREIGN_KEY_CHECKS=0;" if you get the error "a foreign key constraint fails", you obviously have bad data that you must fix or else you will get bigger problems down the line.
– MazeChaZer
Jun 11 '18 at 12:05
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How to get a list of user accounts using the command line in MySQL?
...ing passwords. Omitting the host from the SET PASSWORD command produces an error. SET PASSWORD FOR wordpressuser = PASSWORD('...'); produces the error ERROR 1133 (42000): Can't find any matching row in the user table. Include the host and it works. SET PASSWORD FOR wordpressuser@localhost = PASSWORD...