User kokos answered the wonderful Hidden Features of C# question by mentioning the using keyword. Can you elaborate on that? What are the uses of using?
Updating the using keyword was specifically for templates, and (as was pointed out in the accepted answer) when you are working with non-templates using and typedef are mechanically identical, so the choice is totally up to the programmer on the grounds of readability and communication of intent.
182 In C++11, the using keyword when used for type alias is identical to typedef. 7.1.3.2 A typedef-name can also be introduced by an alias-declaration. The identifier following the using keyword becomes a typedef-name and the optional attribute-specifier-seq following the identifier appertains to that typedef-name.
46 Justin Lessard's answer explains the difference between using and await using, so I'll focus on which one to use. There are two cases: either the two methods Dispose / DisposeAsync are complementary, or they are doing something different.
Extremely good point. Of all the advantages using provides, it can't be combined with other predicates: select*from t join t2 using(i) and on 1 wouldnt work.
But if you put the using declaration inside a namespace it's limited to the scope of that namespace, so is generally OK (with the usual caveats on your particular needs and style).
The using statement is used to work with an object in C# that implements the IDisposable interface. The IDisposable interface has one public method called Dispose that is used to dispose of the object.
A using statement can be exited either when the end of the using statement is reached or if an exception is thrown and control leaves the statement block before the end of the statement.
The problem with putting using namespace in the header files of your classes is that it forces anyone who wants to use your classes (by including your header files) to also be 'using' (i.e. seeing everything in) those other namespaces. However, you may feel free to put a using statement in your (private) *.cpp files.
