Name Space of typedef Names

Names declared using typedef occupy the same name space as other identifiers (except statement labels). Therefore, they cannot use the same identifier as a previously declared name, except in a class-type declaration. Consider the following example:

// typedef_names1.cpp
// C2377 expected
typedef unsigned long UL;   // Declare a typedef name, UL.
int UL;                     // C2377: redefined.

The name-hiding rules that pertain to other identifiers also govern the visibility of names declared using typedef. Therefore, the following example is legal in C++:

// typedef_names2.cpp
typedef unsigned long UL;   // Declare a typedef name, UL
int main()
{
   unsigned int UL;   // Redeclaration hides typedef name
}

// typedef UL back in scope

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