Recently I needed to do some calculations on series where getting close to zero could become a problem.
Math seems to have an Epsilon of 1E-12.
Sytem.Types has Epsilon of 1E-30 and Epsilon2 of 1E-40.
XE4+ FMX has IsEssentiallyZero and IsNotEssentiallyZero for Single values.
In practice it depends a lot on what you are doing. Sometimes absolute Epsilons are best, but at other times relative difference is much more applicable.
Then there is also a Machine Epsilon: a way to derive an Epsilon from a data type that works in all languages and platforms.
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Note that 15.0 (in VS2017) no longer registers itself at this registry key location, so this trick won’t simply work. vswhere is now recommended to locate MSBuild 15,
Ctrl + Shift + . to zoom in and Ctrl + Shift + , to zoom out.
They don’t keep an alternative for Zoom Out, and unlike most tools I know that allow for zooming, there is no keyboard accessible menu entry for Zoom Out in Visual Studio.
So you have to use your mouse to go in the lower left of your editor window in order to Zoom Out (thanks ashteele for putting that in an SO question):
I’ve seen this question coming up a few times, and bumped into this at a client recently: the UAC dialog coming up when debugging a 32-bit executable.
This is caused (more details below) by Installer Detection Technology introduced in Windows Vista (with UAC) and tightened in more modern Windows versions.
The solution is to either:
not include Installer, Patch, Update, Upgrade, Setup, … in your EXE name
provide a correct manifest to your EXE (getting this right can be hard)
StackOverflow user Kenneth Reitz has written a great on-line and free httpbin tool that responds to many kinds of http/https requests including the standaard http request methods (or verbs) used by REST: get, post (for http 1.0) and patch, put, delete (for http 1.1).
These verbs are not supported: head (http 1.0) and trace, options, connect (http 1.1).
The site is geared towards JSON (as most the responses are in JSON, except for one XML response and a few TEXT responses), but even if your environment does not use JSON, it is very useful as you basically get an echo of information on what you pass to it.
Except one endpoint (/encoding/utf8), none of the response encodings can be determined by the request. This is a pity as sometimes it is good to see how a specific encoding works for JSON, but it is very hard to support encodings well, so I can understand the support is not there (or not there yet).
Interesting. And I need to give some thought because when calling Assert.AreEqual<T1, T2>(T1 object1, T2 object2) where T1 does not equal T2 will map to Assert.AreEqual(object, object) without compile time warning.
var str =String.Join(", ",SupportedNotificationMethods.Select(s => s.ToString()));
You can read more about the String.Join method at MSDN. Older versions of String.Join don’t have an overload that takes an IEnumerable. In that case just call ToArray() after select.
If you just care about existence, you could use ContainsValue(0) or Any(p => p.Value == 0) instead? Searching by value is unusual for a Dictionary<,>; if you were searching by key, you could use TryGetValue.
One other approach:
var record = data.Where(p => p.Value==1).Select(p =>new{Key= p.Key,Value= p.Value}).FirstOrDefault();
This returns a class – so will be null if not found.
The trick is this portion:
p =>new{Key= p.Key,Value= p.Value}
It introduces an anonymous type with two fields: Key and Value. (Note you can introduce any anonymous type here). Since these are classes, FirstOrDefault will return null if nothing was found.
The Wiert Corner - irregular stream of stuff 
lextm commented on Mar 9, 2017 •
vswhereis now recommended to locate MSBuild 15,https://github.com/Microsoft/vswhere
n9 commented on May 17, 2017
vswhere -products *to get standalone installation of BuildTools. (See Microsoft/vswhere#61.)