C through the eyes of someone who learned Rust first

A Rust-first programmer explains the C conventions that surprised them: strings end at a null byte, integer widths depend on the target, and array parameters become pointers. C also leaves callers responsible for checking allocation failures and other error signals. The examples show where assumptions formed in Rust can produce incorrect C code.

BD103 · Oct 7, 2026

Why it matters

A useful companion for Rust learners reading operating-system code, native libraries or foreign-function interfaces.

More context

Try the small examples with compiler warnings enabled and check the selected C standard. The article distinguishes C99 boolean support from C23 language primitives and shows why sizeof on an array parameter measures a pointer. Treat its pointer-size examples as platform-specific.

Keep in mind

This is a learner’s account, not a complete C reference or production coding guide. Its string reversal examples have stated limitations, and the author flags imperfect mappings between Rust and C integer types.

Original read