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What is hashCode used for? Is it unique?
...ethod in every controls, items, in WP7, which return a sequence of number. Can I use this hashcode to identify an item? For example I want to identify a picture or a song in the device, and check it whereabout. This could be done if the hashcode given for specific items is unique.
...
std::function and std::bind: what are they, and when should they be used?
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std::bind is for partial function application.
That is, suppose you have a function object f which takes 3 arguments:
f(a,b,c);
You want a new function object which only takes two arguments, defined as:
g(a,b) := f(a, 4, b);
g is a "partial application" of ...
What Makes a Method Thread-safe? What are the rules?
...ly references variables scoped within that method then it is thread safe because each thread has its own stack:
In this instance, multiple threads could call ThreadSafeMethod concurrently without issue.
public class Thing
{
public int ThreadSafeMethod(string parameter1)
{
int numbe...
When to use the brace-enclosed initializer?
...tended to be the exact value of the object, use copy (=) initialization (because then in case of error, you'll never accidentally invoke an explicit constructor, which generally interprets the provided value differently). In places where copy initialization is not available, see if brace initializat...
Why always ./configure; make; make install; as 3 separate steps?
...
Because each step does different things
Prepare(setup) environment for building
./configure
This script has lots of options that you should change. Like --prefix or --with-dir=/foo. That means every system has a different c...
WebAPI Multiple Put/Post parameters
... "Name": "jhon",
"Id": 1,
};
var product = {
"Name": "table",
"CategoryId": 5,
"Count": 100
};
var employee = {
"Name": "Fatih",
"Id": 4,
};
var myData = {};
myData.customerData = customer;
myData.productData = product;
myData.employeeData = employee;
$.ajax({
type: 'PO...
What is the difference between “#!/usr/bin/env bash” and “#!/usr/bin/bash”?
...it in a specific place on the system, as those paths may be in different locations on different systems. As long as it's in your path, it will find it.
One downside is that you will be unable to pass more than one argument (e.g. you will be unable to write /usr/bin/env awk -f) if you wish to suppo...
Difference between Big-O and Little-O Notation
... says, essentially
For at least one choice of a constant k > 0, you can find a constant a such that the inequality 0 <= f(x) <= k g(x) holds for all x > a.
Note that O(g) is the set of all functions for which this condition holds.
f ∈ o(g) says, essentially
For every choice...
MongoDB Many-to-Many Association
...
Depending on your query needs you can put everything in the user document:
{name:"Joe"
,roles:["Admin","User","Engineer"]
}
To get all the Engineers, use:
db.things.find( { roles : "Engineer" } );
If you want to maintain the roles in separate documents ...
Regular expression to match non-ASCII characters?
...not contained in the ASCII character set (0-127, i.e. 0x0 to 0x7F).
You can do the same thing with Unicode:
[^\u0000-\u007F]+
For unicode you can look at this 2 resources:
Code charts list of Unicode ranges
This tool to create a regex filtered by Unicode block.
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