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Assignment in an if statement
... = value as T;
if (t != null)
{
action(t);
}
}
Then call it with:
animal.AsIf<Dog>(dog => {
// Use dog in here
});
Alternatively, you could combine the two:
public static void AsIf<T>(this object value, Action<T> action) where T : class
{
// EVI...
How to 'bulk update' with Django?
...ings like incrementing rows:
from django.db.models import F
Entry.objects.all().update(n_pingbacks=F('n_pingbacks') + 1)
See the documentation.
However, note that:
This won't use ModelClass.save method (so if you have some logic inside it won't be triggered).
No django signals will be emitte...
Call a python function from jinja2
I am using jinja2, and I want to call a python function as a helper, using a similar syntax as if I were calling a macro. jinja2 seems intent on preventing me from making a function call, and insists I repeat myself by copying the function into a template as a macro.
...
std::vector performance regression when enabling C++11
I have found an interesting performance regression in a small C++ snippet, when I enable C++11:
1 Answer
...
What is the use of “assert” in Python?
...t True # nothing happens
>>> assert False
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
AssertionError
Assertions can include an optional message, and you can disable them when running the interpreter.
To print a message if the assertion fails:
ass...
MFC 的SetWindowPos 用法 - C/C++ - 清泛网 - 专注C/C++及内核技术
...window, the window loses its topmost status and is placed at the bottom of all other windows.
HWND_NOTOPMOST= -2 在所有非"普通层"之上的"普通层"
Places the window above all non-topmost windows (that is, behind all topmost windows). This flag has no effect if the window is already a n...
How can I handle R CMD check “no visible binding for global variable” notes when my ggplot2 syntax i
...
Just another warning. aes_string does not allow you to use functions to manipulate the x and y values. Say that you would like to log transform y in which case aes_string(x = 'x.values', y='log(y.values)') of course doesn't work. I use these kind of transformations a...
How can I do division with variables in a Linux shell?
... It has to be noted somewhere on this page that most (if not all) GNU/Linux shells only perform integer operations.
– Skippy le Grand Gourou
Sep 19 '14 at 12:47
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Error - trustAnchors parameter must be non-empty
...and what truststore is being used you can add the property javax.net.debug=all and then filter the logs about truststore. You can also play with the property javax.net.ssl.trustStore to specify a specific truststore. For example :
java -Djavax.net.debug=all -Djavax.net.ssl.trustStore=/Another/...
How to change language settings in R
... of the abbreviations can be found here.
Sys.getenv() gives you a list of all the environment variables that are set.
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