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Django: How to manage development and production settings?
...
The DJANGO_SETTINGS_MODULE environment variable controls which settings file Django will load.
You therefore create separate configuration files for your respective environments (note that they can of course both import * from a sepa...
Casting vs using the 'as' keyword in the CLR
...bject obj) cil managed
{
// Code size 22 (0x16)
.maxstack 8
IL_0000: ldarg.1
IL_0001: isinst MyClass
IL_0006: brfalse.s IL_0015
IL_0008: ldarg.1
IL_0009: castclass MyClass
IL_000e: pop
IL_000f: ldarg.1
IL_0010: call void [mscorlib]System.Console::WriteL...
SQL Add foreign key to existing column
...rst and then re-run the statement.
ALTER TABLE Employees
ADD CONSTRAINT FK_ActiveDirectories_UserID FOREIGN KEY (UserID)
REFERENCES ActiveDirectories(id);
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...
Explicitly calling return in a function or not
...t return. The following plot is created from data selected this way:
bench_nor2 <- function(x,repeats) { system.time(rep(
# without explicit return
(function(x) vector(length=x,mode="numeric"))(x)
,repeats)) }
bench_ret2 <- function(x,repeats) { system.time(rep(
# with explicit return
(funct...
Check if a class has a member function of a given signature
...compile-time. Example from my code (tests if class has member function size_t used_memory() const).
template<typename T>
struct HasUsedMemoryMethod
{
template<typename U, size_t (U::*)() const> struct SFINAE {};
template<typename U> static char Test(SFINAE<U, &U::us...
Javascript regex returning true.. then false.. then true.. etc [duplicate]
...
/^[^-_]([a-z0-9-_]{4,20})[^-_]$/gi;
You're using a g (global) RegExp. In JavaScript, global regexen have state: you call them (with exec, test etc.) the first time, you get the first match in a given string. Call them again and ...
What's the deal with a leading underscore in PHP class methods?
...private with an underscore. In some older classes you'll see /**private*/ __foo() { to give it some extra weight.
I've never heard of developers prefacing all their methods with underscores, so I can't begin to explain what causes that.
...
How to compile a static library in Linux?
...0);
fun2(10);
return 0;
}
lib.h the libs main header
#ifndef LIB_H_INCLUDED
#define LIB_H_INCLUDED
#include "lib1.h"
#include "lib2.h"
#endif
lib1.c first lib source
#include "lib1.h"
#include <stdio.h>
void fun1 ( int x )
{
printf("%i\n",x);
}
lib1.h the corresponding ...
乐高 EV3 实验06 - 屏幕表情与音效，让机器人有点性格 · App Inventor 2 中文网
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How can I detect if the user is on localhost in PHP?
...
You can also use $_SERVER['REMOTE_ADDR'] for which IP address of the client requesting is given by the web server.
$whitelist = array(
'127.0.0.1',
'::1'
);
if(!in_array($_SERVER['REMOTE_ADDR'], $whitelist)){
// not valid
}
...