Parametric polymorphism in Odin

One largest() for ints and floats: $T takes the element type at compile time.

package main

import "core:fmt"

// $T takes the element type at compile time -- parametric polymorphism.
largest :: proc(items: []$T) -> T {
    best := items[0]
    for x in items[1:] {
        if x > best do best = x
    }
    return best
}

main :: proc() {
    ints := []int{3, 41, 12, 55}
    floats := []f64{2.5, 8.75, 1.25}
    fmt.println("largest int:", largest(ints))
    fmt.println("largest float:", largest(floats))
}

How it works

items: []$T binds the slice's element type to T per call site.
The body compares with >; each instantiation checks it for its own T.
largest(ints) and largest(floats) compile to two separate procedures.

Keywords and builtins used here

T
do
f64
for
if
import
in
int
package
proc
return

The run, in numbers

Lines: 19
Characters to type: 391
Tokens: 106
Three-star pace: 65 tpm

At the three-star pace of 65 tokens a minute, this run takes about 98 seconds.

Type this snippet

Step 2 of 3 in Types & generics, step 20 of 27 in Language basics.

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