RustEn8Etapes/etape8/ex8_2.rs

/* Copyright (C) 2011-2023  Patrick H. E. Foubet - E2L Ivry
Ecole du Logiciel Libre : https://e2li.org/

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or any
later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>
*******************************************************************/

struct Cercle{ // créez une structure de type
	rayon : f32, // membre de la structure
}

trait Calculate { // définir un trait
	fn aire(&self) -> f32 ; // Définit une méthode de trait.
}

impl Calculate for Cercle { // implémente la fonction
	fn aire(&self) -> f32 { // implémente la méthode du trait   
		std::f32::consts::PI * self . rayon * self.rayon
	}  
}

fn main(){
let obj = Cercle { rayon : 2000.00} ; // crée un objet structuré
	println ! ("L'aire du cercle est : {}", obj.aire()) ;
    // dans le println on appelle la méthode
}