C# Programming/Keywords/alias

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The alias keyword is used to indicate an external alias.

When you need to use several versions of the same assembly or assemblies with the same full qualified typenames, you need to use the alias and extern keywords to give different alias names for each version.


extern alias AppTools;
extern alias AppToolsV2;

To use the typenames of each version, you have the operator :: .


AppTools::MainTool tool_v1 = new AppTools::MainTool();
AppToolsV2::MainTool tool_v2 = new AppToolsV2::MainTool();

However, this only says to the compiler that there are several assemblies with typename conflicts. To relate what of each assemblies match's the alias name, you have to tell the compiler on its options apart the source. On dotNet command line, this options would be:

/r:AppTools=AppToolsv100.dll /r:AppToolsV2=AppToolsv200.dll

Notice: In order for it to be of use, you need to provide an external assembly to the compiler (e.g. pass /r:EXTALIAS=XXX.dll) and identify the external alias within the code (e.g. extern alias EXTALIAS;)

C# Keywords
abstract as base bool break
byte case catch char checked
class const continue decimal default
delegate do double else enum
event explicit extern false finally
fixed float for foreach
goto if implicit in int
interface internal is lock long
namespace new null object operator
out override params private protected
public readonly ref return sbyte
sealed short sizeof stackalloc
static string struct switch this
throw true try typeof uint
ulong unchecked unsafe ushort using
var virtual void volatile while
Special C# Identifiers
add alias get global partial
remove set value where yield