大约有 6,261 项符合查询结果（耗时：0.0203秒） [XML]
Java Enum definition
...
It still allows me to create a class Foo extends Node<City> where Foo is unrelated to City.
– newacct
Nov 23 '11 at 22:43
1
...
Split string in Lua?
...
Doesn't work if string contains empty values, eg. 'foo,,bar'. You get {'foo','bar'} instead of {'foo', '', 'bar'}
– andras
Sep 19 '16 at 21:38
5
...
Validating parameters to a Bash script
... it as a commentar). i did "$#" to fix it. second, the regex also matches "foo123bar". i fixed it by doing ^[0-9]+$. you may also fix it by using grep's -x option
– Johannes Schaub - litb
Mar 31 '09 at 1:21
...
“for” vs “each” in Ruby
...
Never ever use for it may cause almost untraceable bugs.
Don't be fooled, this is not about idiomatic code or style issues. Ruby's implementation of for has a serious flaw and should not be used.
Here is an example where for introduces a bug,
class Library
def initialize
@ary = []
...
What is move semantics?
...to members
Sooner or later, you are going to write code like this:
class Foo
{
unique_ptr<Shape> member;
public:
Foo(unique_ptr<Shape>&& parameter)
: member(parameter) // error
{}
};
Basically, the compiler will complain that parameter is an lvalue. If you...
How to update PATH variable permanently from Windows command line?
...nvironment:PATH=...
...
> REM ## Query env-var:
> setenv.py PATH C:\foo
!!!Cannot access HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Environment:PATH due to: [WinError 5] Access is denied
!!!Cannot find HKEY_CURRENT_USER\Environment:PATH due to: [WinError 2] The syst...
How do I dump an object's fields to the console?
...
The to_yaml method seems to be useful sometimes:
$foo = {:name => "Clem", :age => 43}
puts $foo.to_yaml
returns
---
:age: 43
:name: Clem
(Does this depend on some YAML module being loaded? Or would that typically be available?)
...
What does the “at” (@) symbol do in Python?
...ons and class definitions
for more about decorators.
So, we see that
@foo
def bar():
pass
is semantically the same as:
def bar():
pass
bar = foo(bar)
They are not exactly the same because Python evaluates the foo expression (which could be a dotted lookup and a function call) befo...
how does array[100] = {0} set the entire array to 0?
...d the initialiser.
If your array is auto, then it is another story.
int foo(void)
{
char array[100] = {0};
...
}
In this case at every call of the function foo you will have a hidden memset.
The code above is equivalent to
int foo(void)
{
char array[100];
memset(array, 0, sizeof(array));
.....
Recursive Lock (Mutex) vs Non-Recursive Lock (Mutex)
...s not efficiency. Non-reentrant mutexes lead to better code.
Example: A::foo() acquires the lock. It then calls B::bar(). This worked fine when you wrote it. But sometime later someone changes B::bar() to call A::baz(), which also acquires the lock.
Well, if you don't have recursive mutexes,...