Re: why use typedef instead of define?

From: Doug Harrison [MVP] (dsh_at_mvps.org)
Date: 10/18/04 

Date: Sun, 17 Oct 2004 22:17:33 -0500

Lisa Pearlson wrote:

>Hi:
>
>what's the difference between:
>
>typedef sometype mytype;
>
>and
>
>#define mytpe sometype

Macros use textual substitution, while typedefs do not. Here are a couple of
cases where it matters:

#define INTP_MACRO int*
typedef int* INTP_TYPEDEF;

INTP_MACRO x, y; // x is int*, y is just int
INTP_TYPEDEF x, y; // Both are int*

const INTP_MACRO p1; // p1 is const int*
INTP_MACRO const p2; // p2 is int* const

const INTP_TYPEDEF p3; // p3 is int* const
INTP_TYPEDEF const p4; // p4 is int* const 

-- 
Doug Harrison
Microsoft MVP - Visual C++

Relevant Pages