Encompassing only entire statements and expressions with preprocessor conditionals.

[ghost]

A suggestion to compile entire statements and expressions, as suggested by code style guidelines from the Linux Kernel and practitioners.

• https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/CodingStyle#n892
• https://www.cqse.eu/en/blog/living-in-the-ifdef-hell/

It might improve code understanding, maintainability and error-proneness.

[richsalz]

this is a good idea, but stdbool and bool are not; use int.

[kaduk]

Declaring variables at inner scope may or may not be a good idea, too. (Does the style guide address this question?)

[levitte]

Style wise, I don't think camelCase is seen in OpenSSL too often.

Regarding inner scope declaration, I don't see anything wrong with it. However having the same variable declared multiple times inside different branches of a preprocessor condition... Nah. Declare outside if the condition, assign inside.