using = <type> directive

[Dylan Nicholson]

Can someone confirm that a) is illegal, and b) the solution?

a)

namespace Test
{
struct MyStruct
{
int a;
int b;
}
using MyQueue = System.Collections.Generic.Queue<MyStruct>;

class MyClass
{
MyQueue q = new MyQueue();
}
}

b)

namespace Test
{
struct MyStruct
{
int a;
int b;
}
}

namespace Test
{
using MyQueue = System.Collections.Generic.Queue<MyStruct>;

class MyClass
{
MyQueue q = new MyQueue();
}
}

If I'm right, anyone else agree that this seems just a little silly?

 

[Nicholas Paldino [.NET/C# MVP]]

Well the compiler is verifying this for you. What don't you believe
about the compiler. It's error message for a) is very specific about what
the issue is, and how to resolve it.

As for it being silly, no, I don't think so, since I think it would be
confusing to be able to have those defined arbitrarily all over the place.
It would make the code difficult to follow, IMO.

 

[Peter Duniho]

Can someone confirm that a) is illegal, and b) the solution?

Well, you could have used, instead of b), this:

namespace Test
{
using MyQueue = System.Collections.Generic.Queue<MyStruct>;

struct MyStruct
{
int a;
int b;
}

class MyClass
{
MyQueue q = new MyQueue();
}
}

[...]
If I'm right, anyone else agree that this seems just a little silly?

The compiler simply requires that the "using" directive come first. It's
about the only "pre-processor"-like thing C# supports, and I wouldn't use
the word "silly" to describe the requirement that the directive come
before any code the compiler will be compiling.

YMMV.

Pete

 

[Dylan Nicholson]

Well, you could have used, instead of b), this:

namespace Test
{
using MyQueue = System.Collections.Generic.Queue<MyStruct>;

struct MyStruct
{
int a;
int b;
}

class MyClass
{
MyQueue q = new MyQueue();
}

}

Ah, well, I thought I'd tried that, and because it put a squiggly line
under "MyStruct" in the using directive when I typed it, I assumed it
wasn't legal. But you're right, this is fine, and not really all that
silly.