Declaring a namespace as a macro - C ++

Question

In the standard library, I found that the namespace is stddeclared as a macro.

#define _STD_BEGIN  namespace std {
#define _STD_END        }

• Is this best practice when using namespaces?
• The macro is declared in Microsoft Visual Studio 9.0\VC\include\yvals.h. But I could not find the STL files, including this. If it is not turned on, how can it be used?

Any thoughts ..?

Answer 1

This is probably not the best practice as it is difficult to read compared to the vanilla declaration namespace. However, remember that the rules are not always applied everywhere, and I am sure that there is some kind of scenario in which a macro can significantly improve the situation.

" STL, . , ?".

, , yvals.h -. , <vector> <memory>, <iterator>, <xutility>, <climits>, <yvals.h>. , - .

, ; .

Answer 2

• , , , .
• . , , , STL.

Answer 3

, - , /, .

Answer 4

, , , :

BEGIN_NAMESPACE_XXX()

XXX - , :

BEGIN_NAMESPACE_3(ns1, ns1, ns3)

namespace ns1 {
    namespace ns2 {
        namespace ns2 {

END_NAMESPACE_3

        }
    }
}

( )

Answer 5

C, ++ (, , C string.h ++ cstring). #ifdef _c_plus_plus.

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