“deduced return type - a type that, for a given function whose return type is represented using the auto keyword, is deduced from (possibly implicit) return statements within the function definition (see Section 1.1.“Trailing Return” on page 124); note that auto at the start of a function declaration might instead be used to introduce a trailing, but nonetheless explicit, return type (see Section 1.1.“Trailing Return” on page 124). Lambdas (593)” (EMCppSfe 2021)