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Why doesn't GCC optimize a*a*a*a*a*a to (a*a*a)*(a*a*a)?
...scientific application. One thing I noticed is that GCC will optimize the call pow(a,2) by compiling it into a*a , but the call pow(a,6) is not optimized and will actually call the library function pow , which greatly slows down the performance. (In contrast, Intel C++ Compiler , executable ...
“Variable” variables in Javascript?
...usly consider that). It is possible to access some global variables dynamically via window, but that doesn't work for variables local to a function. Global variables that do not become a property of window are variables defined with let and const, and classes.
There is almost always a better soluti...
UnicodeDecodeError when reading CSV file in Pandas with Python
...= "ISO-8859-1"), or alternatively encoding = "utf-8" for reading, and generally utf-8 for to_csv.
You can also use one of several alias options like 'latin' instead of 'ISO-8859-1' (see python docs, also for numerous other encodings you may encounter).
See relevant Pandas documentation,
python doc...
SQLAlchemy: how to filter date field?
...In fact, your query is right except for the typo: your filter is excluding all records: you should change the <= for >= and vice versa:
qry = DBSession.query(User).filter(
and_(User.birthday <= '1988-01-17', User.birthday >= '1985-01-17'))
# or same:
qry = DBSession.query(User)....
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 do I find where JDK is installed on my windows machine?
...
Actually, the form %VAR_NAME% is Windows
– sblundy
Jan 13 '11 at 14:29
2
...
What column type/length should I use for storing a Bcrypt hashed password in a Database?
... I don't get the reason why I should bother about binary or not binary at all, if I don't want to sort by password hash, compare hashes on database layer or make the password column unique (“Sorry, this password is already in use”) at all. I'd recommend using UTF8 everywhere. In that case there...
What does 'require: false' in Gemfile mean?
...
This means install the gem, but do not call require when you start Bundler. So you will need to manually call
require "whenever"
if you want to use the library.
If you were to do
gem "whenever", require: "whereever"
then bundler woul...
Error 1022 - Can't write; duplicate key in table
...ou can not have the same foreign key names in the database tables.
Check all your tables and all your foreign keys and avoid having two foreign keys with the same exact name.
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improve this ...
Using the Android Application class to persist data
..., the Application class does not have the same life-cycle (i.e. it is, for all intents and purposes, always instantiated). Does it make sense to store the state information inside of the application class and then reference it from the Activity, or is that generally not the "acceptable" method due ...