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Java: Instanceof and Generics
...(Object o) {
try {
abstractMethod((T) o);
} catch (ClassCastException e) {
//...
You are casting the object to T (your generic type), just to fool the compiler. Your cast does nothing at runtime, but you will still get a ClassCastException when you try to pass the wrong type of...
Converting java.util.Properties to HashMap
...
The efficient way to do that is just to cast to a generic Map as follows:
Properties props = new Properties();
Map<String, String> map = (Map)props;
This will convert a Map<Object, Object> to a raw Map, which is "ok" for the compiler (only warning)....
Resolving MSB3247 - Found conflicts between different versions of the same dependent assembly
...ing up the Options dialog (Tools -> Options...).
In the left-hand tree, select the Projects and Solutions node, and then select Build and Run.
Note: if this node doesn't show up, make sure that the checkbox at the bottom of the dialog Show all settings is checked.
In the tools/options page th...
How to get the caller's method name in the called method?
...ccessing.
import inspect
from types import FrameType
from typing import cast
def caller_name() -> str:
"""Return the calling function's name."""
# Ref: https://stackoverflow.com/a/57712700/
return cast(FrameType, cast(FrameType, inspect.currentframe()).f_back).f_code.co_name
if...
Run a string as a command within a Bash script
...rameters so I ended up with something like:
my_exe ()
{
mysql -sN -e "select $1 from heat.stack where heat.stack.name=\"$2\";"
}
This is something I use to monitor openstack heat stack creation. In this case I expect two conditions, an action 'CREATE' and a status 'COMPLETE' on a stack named ...
Should you choose the MONEY or DECIMAL(x,y) datatypes in SQL Server?
...@num2 DECIMAL(19,4),
@num3 DECIMAL(19,4),
@num4 DECIMAL(19,4)
SELECT
@mon1 = 100, @mon2 = 339, @mon3 = 10000,
@num1 = 100, @num2 = 339, @num3 = 10000
SET @mon4 = @mon1/@mon2*@mon3
SET @num4 = @num1/@num2*@num3
SELECT @mon4 AS moneyresult,
@num4 AS numericresult...
Comparing boxed Long values 127 and 128
...val4); // true
(Proper null checking is necessary, even for castings)
IMO, it's always a good idea to stick with .equals() methods when dealing with Object comparisons.
Reference links:
https://today.java.net/pub/a/today/2005/03/24/autoboxing.html
https://blogs.oracle.com/darcy/en...
How can I return an empty IEnumerable?
...rExists) yield break; foreach(var descendant in doc.Descendants("user").Select(user => new Friend { ID = user.Element("id").Value, Name = user.Element("name").Value, URL = user.Element("url").Value, Photo = user.Element("photo").Value })) { yield r...
Can I use if (pointer) instead of if (pointer != NULL)?
...s, so readability or conciseness isn't that much of an issue here.
Dynamic casts. Casting a base-class pointer to a particular derived-class one (something you should again try to avoid, but may at times find necessary) always succeeds, but results in a null pointer if the derived class doesn't matc...
ThreadStart with parameters
...
+1: Even though the currently selected answer is absolutely correct, this one by JaredPar is the better one. It simply is the best solution for most practical cases.
– galaktor
Oct 10 '09 at 10:27
...