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What does default(object); do in C#?
... value
For Nullable<T> it returns the empty (pseudo-null) value (actually, this is a re-statement of the first bullet, but it is worth making it explicit)
The biggest use of default(T) is in generics, and things like the Try... pattern:
bool TryGetValue(out T value) {
if(NoDataIsAvailab...
Why do I have to access template base class members through the this pointer?
...emplate parameter. Others are deferred until the parameter is known. It's called two-phase compilation, and MSVC doesn't do it but it's required by the standard and implemented by the other major compilers. If you like, the compiler must compile the template as soon as it sees it (to some kind of in...
echo that outputs to stderr
...criptors will refer to the same file: the one file descriptor #2 was originally referring to. For more information see the Bash Hackers Illustrated Redirection Tutorial.
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Private pages for a private Github repo
... support ticket against Github and got a response confirming the fact that ALL pages are public. I've now requested them to add a note to help.github.com/pages.
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shortcut for creating a Map from a List in groovy?
...
Check out "inject". Real functional programming wonks call it "fold".
columns.inject([:]) { memo, entry ->
memo[entry.name] = entry.val
return memo
}
And, while you're at it, you probably want to define methods as Categories instead of right on the metaClass. That ...
Why doesn't JUnit provide assertNotEquals methods?
...st you use the newer assertThat() style asserts, which can easily describe all kinds of negations and automatically build a description of what you expected and what you got if the assertion fails:
assertThat(objectUnderTest, is(not(someOtherObject)));
assertThat(objectUnderTest, not(someOtherObjec...
Best practices for SQL varchar column length [closed]
...ax length that is not a power of 2.
I think early SQL Server versions actually treated a VARCHAR with length 255 differently than one with a higher maximum length. I don't know if this is still the case.
For almost all DBMS, the actual storage that is required is only determined by the number of ...
Mongoose and multiple database in single node.js project
... thing you can do is, you might have subfolders for each projects. So, install mongoose in that subfolders and require() mongoose from own folders in each sub applications. Not from the project root or from global. So one sub project, one mongoose installation and one mongoose instance.
-app_root/
...
Is the practice of returning a C++ reference variable evil?
...
In general, returning a reference is perfectly normal and happens all the time.
If you mean:
int& getInt() {
int i;
return i; // DON'T DO THIS.
}
That is all sorts of evil. The stack-allocated i will go away and you are referring to nothing. This is also evil:
int& get...
Can a local variable's memory be accessed outside its scope?
...said that if you leave stuff behind, they'll shred it for you. If you illegally re-enter your room with a stolen key to get it back, the hotel security staff is not required to catch you sneaking in. You didn't make a contract with them that said "if I try to sneak back into my room later, you are r...
