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This post is auto-generated from RSS feed The Rust Programming Language Forum - Latest topics. Source: Functions with a body ending with a statement

We all know, that a Rust function returns the unit type () when the function body ends not with an expression but with a statement.

In the official book this is explained a bit un-precise, so we just had a longer discussion in the GitHub issue tracker. Indeed it is difficult to find a precise explanation. One problem is, that some documentation says, that a statement in Rust has no value at all, but other say that a statement has the value of the unit type ().

In my own book, I have the following text:

"Important: Adding a semicolon ; after the final expression [in the function] turns it into a statement. Statements evaluate to the unit type (). If a function is expected to return a value (e.g., -> i32), ending it with a statement like a * b; will result in a type mismatch error, because the function implicitly returns () instead of the expected i32."

I still believe this is correct, but someone in the issue tracker has some doubts, and so I am not fully sure as well.

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