Conditionally set a variable if it's NULL

Question

When stepping through a sqlite3_stmt, I\'d like to check against a return value of NULL rather than store it and check against the stored value.

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Answer 1

A GNU extension to C allows the ternary conditional operator to evaluate to its condition if it's true and there's nothing in the first branch:

char *email = (char *)sqlite3_column_text(statement, 10);
email = email ? : "";

or, more exactly what you say you're looking for

char * email = (char *)sqlite3_column_text(statement, 10) ? : "";

This works when compiling with Clang, too.

Another possibility would be:

char *email = (char *)sqlite3_column_text(statement, 10);
email = (NULL == email) ? email : "";

But I think I'd recommend just going with your first option. Make a code snippet if you're doing it a lot.

Answer 2

Does this work?

char *email;
// Reviewed by "R." to verify sequence point correctness.
email = (email = (char *)sqlite3_column_text(statement, 10))? email : "";