DOCUMENT:Q149753  03-NOV-1999  [fortran]
TITLE   :How to Determine the Size of a User-Defined Data Type
PRODUCT :Microsoft Fortran Compiler
PROD/VER::4.0
OPER/SYS:
KEYWORDS:kbcode kbFortranPS kbLangFortran

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The information in this article applies to:

 - Microsoft Fortran PowerStation for Windows 95 and Windows NT, version 4.0 
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SUMMARY
=======

The Fortran Run-Time Library included with Microsoft Fortran PowerStation
version 4.0 does not include an intrinsic function or subroutine that can return
the number of bytes in use by a single user-defined data type variable. You can,
however, use the LOC() intrinsic function to obtain the starting addresses of
two user-defined data type variables, contiguous in memory, and subtract their
addresses resulting in the number of bytes used by one variable of this type.

MORE INFORMATION
================

Do the following to calculate the number of bytes in use by a single user-
defined data type variable:

1. Create a two-element array variable of any user-defined data type.

2. Use the LOC() intrinsic function to obtain the starting memory addresses for
   both user-defined data type array elements.

3. Subtract these addresses from each other. This will yield the number of bytes
   used in memory by this type of user-defined variable.

Sample Code to Illustrate Technique
-----------------------------------

   C Compile options needed: none
         type udt
             integer a
             real b
         end type
         type (udt) myt(2)
         print *, 'Number of bytes used: ', loc(myt(2)) - loc(myt(1))
         end

Program Output
--------------

Number of bytes used: 8

Additional query words: 4.00 kbinf

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Keywords          : kbcode kbFortranPS kbLangFortran 
Technology        : kbAudDeveloper kbPTProdChange kbFortranSearch kbFORTRANPower400NT
Version           : :4.0

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