Simple Bench to test dynamic and static dispatching on Rust.

bench.rs

use std::env;
use std::io;
use std::option::Option;


struct StructTest {
	any_value: i32
}


trait TraitDynamicDispatch {
    fn call(&mut self, func: &mut FnMut(i32) -> i32) -> Option<io::Result<()>>;
}

impl TraitDynamicDispatch for StructTest {
    fn call(&mut self, func: &mut FnMut(i32) -> i32) -> Option<io::Result<()>> {
    	//just do some calc
    	let mut sum: i32 = 0;
    	for i in 1..3 {
    		sum += func(i);
    	}
        if sum != self.any_value {        	
            Some(Ok(()))
        } else {
            None
        }
    }
}


trait TraitFunctionPointer {
    fn call(&mut self, func: fn(i32) -> i32) -> Option<io::Result<()>>;
}

impl TraitFunctionPointer for StructTest {
    fn call(&mut self, func: fn(i32) -> i32) -> Option<io::Result<()>> {
    	//just do some calc
    	let mut sum: i32 = 0;
    	for i in 1..3 {
    		sum += func(i);
    	}
        if sum != self.any_value {        	
            Some(Ok(()))
        } else {
            None
        }
    }
}

impl StructTest {
    fn call_static_dispatch<F>(&mut self, func: &mut F) -> Option<io::Result<()>>
    	where F: FnMut(i32) -> i32 {
    	//just do some calc
    	let mut sum: i32 = 0;
    	for i in 1..3 {
    		sum += func(i);
    	}
        if sum != self.any_value {        	
            Some(Ok(()))
        } else {
            None
        }
    }


    fn call_function_pointer(&mut self, func: fn(i32) -> i32) -> Option<io::Result<()>> {
    	//just do some calc
    	let mut sum: i32 = 0;
    	for i in 1..3 {
    		sum += func(i);
    	}
        if sum != self.any_value {        	
            Some(Ok(()))
        } else {
            None
        }
    }
}

fn main (){

	fn func(x: i32) -> i32 { x * 3 };
	let mut clos = |x: i32| -> i32 { x * 3 };

	match env::args().nth(1) {
		Some(s_arg) => 
			match s_arg.as_ref() {
				"tdyn" => {
					let mut trait_dynamic_dispatch : &mut TraitDynamicDispatch = &mut StructTest { any_value: 0};
					for _ in 1..30000000 {
						trait_dynamic_dispatch.call(&mut clos);
					}
				},
				"tfun" => {
					let mut trait_function_pointer : &mut TraitFunctionPointer = &mut StructTest { any_value: 0};
					for _ in 1..30000000 {
						trait_function_pointer.call(func);
					}
				},
				"ssta" => {
					let mut struct_static_dispatch = StructTest{ any_value: 0};
					for _ in 1..30000000 {
						struct_static_dispatch.call_static_dispatch(&mut clos);
					}
				},
				"sfun" => {
					let mut struct_function_pointer = StructTest{ any_value: 0};
					for _ in 1..30000000 {
						struct_function_pointer.call_function_pointer(func);
					}
				},
				_ => panic!()
			}
		,
		None => panic!()
    }
}

/*
for type in "tdyn" "tfun" "ssta" "sfun"; do                                                                                                   :(
	for i in $(seq 5); do
		time ./bench ${type}
	done
done

Trait Dynamic Dispatch
./bench tdyn  3.38s user 0.00s system 100% cpu 3.386 total
./bench tdyn  3.38s user 0.01s system 100% cpu 3.389 total
./bench tdyn  3.39s user 0.00s system 100% cpu 3.391 total
./bench tdyn  3.39s user 0.01s system 100% cpu 3.399 total
./bench tdyn  3.39s user 0.00s system 99% cpu 3.390 total

Trait Function Pointer
./bench tfun  3.27s user 0.00s system 100% cpu 3.276 total
./bench tfun  3.26s user 0.00s system 100% cpu 3.259 total
./bench tfun  3.26s user 0.01s system 100% cpu 3.266 total
./bench tfun  3.27s user 0.00s system 100% cpu 3.272 total
./bench tfun  3.25s user 0.00s system 100% cpu 3.254 total

Struct Static Dispatch
./bench ssta  3.31s user 0.00s system 100% cpu 3.307 total
./bench ssta  3.30s user 0.01s system 100% cpu 3.303 total
./bench ssta  3.30s user 0.00s system 100% cpu 3.294 total
./bench ssta  3.32s user 0.00s system 100% cpu 3.324 total
./bench ssta  3.30s user 0.01s system 100% cpu 3.310 total

Struct Function Pointer
./bench sfun  3.27s user 0.00s system 100% cpu 3.267 total
./bench sfun  3.27s user 0.00s system 100% cpu 3.269 total
./bench sfun  3.29s user 0.00s system 100% cpu 3.286 total
./bench sfun  3.27s user 0.00s system 100% cpu 3.270 total
./bench sfun  3.27s user 0.00s system 100% cpu 3.269 total
*/