gtpc2mecC/C++ Language Support User's Guide

TO2_makeEmpty-Delete All Elements from a Collection

This function reinitializes a collection and discards any elements in the collection.

Format

#include <c$to2.h>
long TO2_makeEmpty (const TO2_PID_PTR   pid_ptr,
                          TO2_ENV_PTR   env_ptr);

pid_ptr
The pointer to the persistent identifier (PID) assigned to the collection that will be deleted.

env_ptr
The pointer to the environment as returned by the TO2_createEnv function.

Normal Return

The normal return is a positive value.

Error Return

An error return is indicated by a zero. When zero is returned, use the TO2_getErrorCode function to determine the specific error code. For more information, see Error Handling.

The following error codes are common for this function:

TO2_ERROR_ENV

TO2_ERROR_METHOD

TO2_ERROR_PID

TO2_ERROR_ZERO_PID

Programming Considerations

A commit scope will be created for the TO2_makeEmpty request. If the request is successful, the scope will be committed. If an error occurs while processing the TO2_makeEmpty request, the scope will be rolled back.

Examples

The following example deletes all the elements from a collection.

#include <c$to2.h>          /* Needed for TO2 API functions      */
#include <stdio.h>          /* APIs for standard I/O functions   */
TO2_ENV_PTR    env_ptr;     /* PTR to the TO2 environment        */
TO2_PID        collect;     /* PTR to PID return field           */

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if (TO2_makeEmpty(&collect, env_ptr) == TO2_ERROR) { printf("TO2_makeEmpty failed!\n"); process_error(env_ptr); } else { printf("TO2_makeEmpty successful!\n"); }

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