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How do I get around type erasure on Scala? Or, why can't I get the type parameter of my collections?
...hese instances are objects, you can pass them around, store them, and generally call methods on them. With the support of implicit parameters, it becomes a very powerful tool. Take the following example, for instance:
object Registry {
import scala.reflect.Manifest
private var map= Map.empty[...
Django migration strategy for renaming a model and relationship fields
...n files (!).
Update: As ceasaro mentions, newer versions of Django are usually able to detect and ask if a model is renamed. So try manage.py makemigrations first and then check the migration file.
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Get bitcoin historical data [closed]
...ocket in higher resolution over longer time period you could use script log_bitstamp_trades.py below.
The script uses python websocket-client and pusher_client_python libraries, so install them.
#!/usr/bin/python
import pusherclient
import time
import logging
import sys
import datetime
import sig...
Command-line Tool to find Java Heap Size and Memory Used (Linux)?
...tion which options of jstat one should use in order to verify just the overall memory usage of a JVM? Let's say you start the JVM with Xms=4g and Xmx=4g and you want to see, how much memory of that is already used?
– basZero
Feb 5 '14 at 9:44
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Making a property deserialize but not serialize with json.net
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There are actually several fairly simple approaches you can use to achieve the result you want.
Let's assume, for example, that you have your classes currently defined like this:
class Config
{
public Fizz ObsoleteSetting { get; set;...
Using Regular Expressions to Extract a Value in Java
... answered Oct 25 '08 at 21:47
Allain LalondeAllain Lalonde
83.5k6666 gold badges172172 silver badges234234 bronze badges
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How can I use “sizeof” in a preprocessor macro?
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Following snippets will produce no code if sizeof(someThing) equals PAGE_SIZE; otherwise they will produce a compile-time error.
1. C11 way
Starting with C11 you can use static_assert (requires #include <assert.h>).
Usage:
static_assert(sizeof(someThing) == PAGE_SIZE, "Data structure do...
Argparse: Required arguments listed under “optional arguments”?
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Parameters starting with - or -- are usually considered optional. All other parameters are positional parameters and as such required by design (like positional function arguments). It is possible to require optional arguments, but this is a bit against their desig...
define() vs. const
... a static scalar (number, string or other constant like true, false, null, __FILE__), whereas define() takes any expression. Since PHP 5.6 constant expressions are allowed in const as well:
const BIT_5 = 1 << 5; // Valid since PHP 5.6 and invalid previously
define('BIT_5', 1 << 5); /...
App Inventor 2 JSON数据解析教程 - 解析API返回的JSON数据 · App Inventor 2 中文网
... path（高级技巧）
list by walking key path 配合 walk all at level 可以一步到位：
提取所有 first_name：
global data = Web1.JsonTextDecodeWithDictionaries(global_responseContent)
global firstNames = walkKeyPath(global_data, createList("people", "walk all at level", ...