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When should I use a struct rather than a class in C#?
...e that when a struct implements an interface - as Enumerator does - and is cast to that implemented type, the struct becomes a reference type and is moved to the heap. Internal to the Dictionary class, Enumerator is still a value type. However, as soon as a method calls GetEnumerator(), a reference-...
Find difference between timestamps in seconds in PostgreSQL
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SELECT (cast(timestamp_1 as bigint) - cast(timestamp_2 as bigint)) FROM table;
In case if someone is having an issue using extract.
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GetType() can lie?
...eLine("NiceFoo really is a '{0}'", typeof(NiceFoo));
Console.ReadLine();
Cast the instance to an object and call the GetType() Method
IFoo badFoo = new BadFoo();
IFoo niceFoo = new NiceFoo();
Console.WriteLine("BadFoo says he's a '{0}'", badFoo.GetType().ToString());
Console.WriteLine("NiceFoo ...
How to declare a variable in a PostgreSQL query
...ars.id')::int;
Config settings are always varchar values, so you need to cast them to the correct data type when using them. This works with any SQL client whereas \set only works in psql
The above requires Postgres 9.2 or later.
For previous versions, the variable had to be declared in postgre...
How to sort an array of associative arrays by value of a given key in PHP?
...es from the comparison function, such as float, will result in an internal cast to integer of the callback's return value. So values such as 0.99 and 0.1 will both be cast to an integer value of 0, which will compare such values as equal.
This is an important trap to bear in mind when using usort ...
What is move semantics?
I just finished listening to the Software Engineering radio podcast interview with Scott Meyers regarding C++0x . Most of the new features made sense to me, and I am actually excited about C++0x now, with the exception of one. I still don't get move semantics ... What is it exactly?
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Compile time string hashing
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You were missing a compile flag. Moreover I had to cast to size_t the value -1 in stop recursion template function. The updated version is available here (working from Clang 3.3) : goo.gl/vPMkfB
– Clement JACOB
May 23 '14 at 12:51
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c++11右值引用、std::move移动语义、std::forward完美转发的一些总结 - C/C...
...语义。从实现上讲，它基本等同于一个类型转换：static_cast<T&&>(lvalue);特别
std::move 实际上并不能移动任何东西，它唯一的功能是将一个左值强制转换为右值引用，继而用于移动语义。从实现上讲，它基本等同于一个类型转换...
How to get a function name as a string?
...the above error, consider:
import inspect
import types
from typing import cast
this_function_name = cast(types.FrameType, inspect.currentframe()).f_code.co_name
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Swift - which types to use? NSString or String
...wift type, as in str.bridgeToObjectiveC().length for example. You can also cast a String to an NSString by using str as NSString.
However, the necessity for these techniques to explicitly use the Foundation types, or at least some of them, may be obsolete in the future, since from what is stated in...