大约有 17,000 项符合查询结果（耗时：0.0458秒） [XML]
How do you build a Singleton in Dart?
...t's easy to build a singleton:
class Singleton {
static final Singleton _singleton = Singleton._internal();
factory Singleton() {
return _singleton;
}
Singleton._internal();
}
You can construct it like this
main() {
var s1 = Singleton();
var s2 = Singleton();
print(identical(...
How to parse/read a YAML file into a Python object? [duplicate]
...e looks like this:
import yaml
with open('tree.yaml') as f:
# use safe_load instead load
dataMap = yaml.safe_load(f)
The variable dataMap now contains a dictionary with the tree data. If you print dataMap using PrettyPrint, you will get something like:
{'treeroot': {'branch1': {'branch1-...
Why is `std::move` named `std::move`?
...
template <class T>
void
swap(T& a, T& b)
{
T tmp(static_cast<T&&>(a));
a = static_cast<T&&>(b);
b = static_cast<T&&>(tmp);
}
One has to recall that at this point in history, the only thing that "&&" could possibly mean w...
How do I calculate the date in JavaScript three months prior to today?
...tedMonth) {
result.setDate(0);
}
return result;
}
var dt2004_05_31 = new Date("2004-05-31 0:00"),
dt2001_05_31 = new Date("2001-05-31 0:00"),
dt2001_03_31 = new Date("2001-03-31 0:00"),
dt2001_02_28 = new Date("2001-02-28 0:00"),
result = addMonths(dt2001_05_31, -2...
Should import statements always be at the top of a module?
...ent libraries, don't break if an optional library is not installed.
In the __init__.py of a plugin, which might be imported but not actually used. Examples are Bazaar plugins, which use bzrlib's lazy-loading framework.
shar...
Meaning of @classmethod and @staticmethod for beginner? [duplicate]
...thod can have no parameters at all.
Example
class Date(object):
def __init__(self, day=0, month=0, year=0):
self.day = day
self.month = month
self.year = year
@classmethod
def from_string(cls, date_as_string):
day, month, year = map(int, date_as_string...
Where and how is the _ViewStart.cshtml layout file linked?
...rting with the ASP.NET MVC 3 Beta release, you can now add a file
called _ViewStart.cshtml (or _ViewStart.vbhtml for VB) underneath the
\Views folder of your project:
The _ViewStart file can be used to define common view code that you
want to execute at the start of each View’s renderin...
Is gcc 4.8 or earlier buggy about regular expressions?
....
Seriously though, who though that shipping an implementation of regex_search that only does "return false" was a good idea?
It wasn't such a bad idea a few years ago, when C++0x was still a work in progress and we shipped lots of partial implementations. No-one thought it would remain unusab...
How do I pass a method as a parameter in Python
...thodToRun()
return result
obj.method2(obj.method1)
Note: I believe a __call__() method does exist, i.e. you could technically do methodToRun.__call__(), but you probably should never do so explicitly. __call__() is meant to be implemented, not to be invoked from your own code.
If you wanted me...
Entity Framework rollback and remove bad migration
...g migrations that have been applied to the target database.
201508242303096_Bad_Migration
201508211842590_The_Migration_applied_before_it
201508211440252_And_another
This list shows the most recent applied migrations first. Pick the migration that occurs in the list after the one you want to downgr...