gtpc2mfe | C/C++ Language Support User's Guide |
This function determines if the collection contains any elements.
Format
#include <c$to2.h> BOOL TO2_isEmpty (const TO2_PID_PTR cursorPidPtr, TO2_ENV_PTR env_ptr);
Normal Return
Error Return
An error return is indicated by a zero. When zero is returned, use the TO2_getErrorCode function to determine the specific error code. This function must also be used with a TO2_IS_FALSE return code to distinguish this return from an error return indication. If the error code returned by TO2_getErrorCode is TO2_IS_FALSE (0), this is the actual return code by the function. Otherwise, an error is indicated. For more information, see Error Handling.
The following error codes are common for this function:
TO2_ERROR_ENV
TO2_ERROR_METHOD
TO2_ERROR_PID
TO2_ERROR_ZERO_PID
Programming Considerations
Examples
The following example tests the cursor to see if the collection contains any elements.
#include <c$to2.h> /* Needed for TO2 API Functions */ #include <stdio.h> /* APIs for standard I/O functions */ TO2_PID cursor; TO2_ENV_PTR env_ptr; TO2_ERR_CODE err_code; /* TO2 error code value */ TO2_ERR_TEXT_PTR err_text_ptr; /* TO2 error code text pointer */
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/************************************************************************/ /* Is the cursor pointing to an empty collection? */ /************************************************************************/ if (TO2_isEmpty(&cursor, env_ptr)) == TO2_IS_FALSE) { err_code = TO2_getErrorCode(env_ptr); if (err_code ! = 0) { printf("TO2_isEmpty failed!\n"); process_error(env_ptr); } else printf("The cursor is not pointing to an empty collection!\n"); } else printf("The cursor is pointing to an empty collection.\n");
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