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Understanding implicit in Scala
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In scala implicit works as:
Converter
Parameter value injector
Extension method
There are 3 types of use of Implicit
Implicitly type conversion : It converts the error producing assignment into intended type
val x :String = "1"
val y:Int = x
String...
How to export DataTable to Excel
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Try simple code, to convert DataTable to excel file as csv:
var lines = new List<string>();
string[] columnNames = dataTable.Columns
.Cast<DataColumn>()
.Select(column => column.ColumnName)
.ToArray();
var header = ...
Algorithm to get the excel-like column name of a number
I'm working on a script that generate some Excel documents and I need to convert a number into its column name equivalent. For example:
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postgresql - sql - count of `true` values
...his works:
SELECT count(*) AS total
, sum(myCol::int) AS countTrue --convert Boolean to Integer
FROM yourTable
;
or better (to avoid :: and use standard SQL syntax):
SELECT count(*) AS total
, sum(CAST(myCol AS int)) AS countTrue --convert Boolean to Integer
FROM yourTable
;
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How to properly check if std::function is empty in C++11?
... an empty lambda doesn't really make sense. Behind the scenes the compiler converts a lambda expression into a struct (or class) definition, with the variables you capture stored as data members of this struct. A public function call operator is also defined, which is what allows you to invoke the l...
How to remove a column from an existing table?
...he real challenge is finding all foreign keys. You can do this by querying system tables or using third party tools such as ApexSQL Search (free) or Red Gate Dependency tracker (premium but more features). There a whole thread on foreign keys here
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Default template arguments for function templates
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On Windows, with all versions of Visual Studio you can convert this error (C4519) to a warning or disable it like so:
#ifdef _MSC_VER
#pragma warning(1 : 4519) // convert error C4519 to warning
// #pragma warning(disable : 4519) // disable error C4519
#endif
See more details ...
Type converting slices of interfaces
I'm curious why Go does't implicitly convert []T to []interface{} when it will implicitly convert T to interface{} . Is there something non-trivial about this conversion that I'm missing?
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Using Custom Domains With IIS Express
...re
Let's use your example of the DNS name dev.example.com
edit %windows%\system32\drivers\etc\hosts file to map dev.example.com to 127.0.0.1 (admin privilege required). If you control DNS server (like in Nick's case) then the DNS entry is sufficient as this step is not needed.
If you access intern...
What does [ N … M ] mean in C aggregate initializers?
..., write [first ... last] = value. This is a GNU extension. For example,
int widths[] = { [0 ... 9] = 1, [10 ... 99] = 2, [100] = 3 };
It is not portable. Compiling with -pedantic with tell you so.
How does it work here?
The preprocessor replaces #include <asm/unistd.h> with its actual c...