Jenerik Fonksiyonlar
Rust supports generics, which lets you abstract algorithms or data structures (such as sorting or a binary tree) over the types used or stored.
/// Pick `even` or `odd` depending on the value of `n`. fn pick<T>(n: i32, even: T, odd: T) -> T { if n % 2 == 0 { even } else { odd } } fn main() { println!("picked a number: {:?}", pick(97, 222, 333)); println!("picked a string: {:?}", pick(28, "dog", "cat")); }
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Rust infers a type for T based on the types of the arguments and return value.
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In this example we only use the primitive types
i32
and&str
forT
, but we can use any type here, including user-defined types:struct Foo { val: u8, } pick(123, Foo { val: 7 }, Foo { val: 456 });
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This is similar to C++ templates, but Rust partially compiles the generic function immediately, so that function must be valid for all types matching the constraints. For example, try modifying
pick
to returneven + odd
ifn == 0
. Even if only thepick
instantiation with integers is used, Rust still considers it invalid. C++ would let you do this. -
Generic code is turned into non-generic code based on the call sites. This is a zero-cost abstraction: you get exactly the same result as if you had hand-coded the data structures without the abstraction.