大约有 6,261 项符合查询结果（耗时：0.0225秒） [XML]
PHP abstract properties
...checks (say, in the constructor) for the $tablename variable, e.g.:
class Foo_Abstract {
public final function __construct(/*whatever*/) {
if(!isset($this->tablename))
throw new LogicException(get_class($this) . ' must have a $tablename');
}
}
To enforce this for all derived clas...
Declaration of Methods should be Compatible with Parent Methods in PHP
...ls which may fail at run-time. Suppose you have
class A { public function foo($a = 1) {;}}
class B extends A { public function foo($a) {;}}
function bar(A $a) {$a->foo();}
The compiler only checks the call $a->foo() against the requirements of A::foo() which requires no parameters. $a may h...
What is your single most favorite command-line trick using Bash? [closed]
...
Renaming/moving files with suffixes quickly:
cp /home/foo/realllylongname.cpp{,-old}
This expands to:
cp /home/foo/realllylongname.cpp /home/foo/realllylongname.cpp-old
share
...
How does the Comma Operator work
...n whatsoever if it does not affect the final result (e.g. false && foo() will skip the call to foo). This is however not the case for comma operator and the above steps will always happen*.
In practice, the default comma operator works almost the same way as a semicolon. The difference is t...
Why does this async action hang?
...nd a common mistake with the TPL, so don't feel bad.
When you write await foo, the runtime, by default, schedules the continuation of the function on the same SynchronizationContext that the method started on. In English, let's say you called your ExecuteAsync from the UI thread. Your query runs on...
How to get the request parameters in Symfony 2?
...Foundation\Request;
public function updateAction(Request $request)
{
$foo = $request->get('foo');
$bar = $request->get('bar');
}
Another option is to introduce your parameters into your action function definition:
use Symfony\Component\HttpFoundation\Request;
public function updat...
What is monkey patching?
...monkey-patching in the Pandas documentation:
import pandas as pd
def just_foo_cols(self):
"""Get a list of column names containing the string 'foo'
"""
return [x for x in self.columns if 'foo' in x]
pd.DataFrame.just_foo_cols = just_foo_cols # monkey-patch the DataFrame class
df = pd....
Is gcc's __attribute__((packed)) / #pragma pack unsafe?
...lude <stdio.h>
#include <stddef.h>
int main(void)
{
struct foo {
char c;
int x;
} __attribute__((packed));
struct foo arr[2] = { { 'a', 10 }, {'b', 20 } };
int *p0 = &arr[0].x;
int *p1 = &arr[1].x;
printf("sizeof(struct foo) = %d\n", (...
How do I use a custom deleter with a std::unique_ptr member?
...signatures:
Bar* create();
void destroy(Bar*);
You can write your class Foo like this
class Foo {
std::unique_ptr<Bar, void(*)(Bar*)> ptr_;
// ...
public:
Foo() : ptr_(create(), destroy) { /* ... */ }
// ...
};
Notice that you don't need to write any lambda or custom...
How does the C code that prints from 1 to 1000 without loops or conditional statements work?
...
foo(arg) and (&foo)(arg) are equivalent, they call foo with argument arg. newty.de/fpt/fpt.html is an interesting page about function pointers.
– Mat
Oct 29 '11 at 8:57
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