Function testbench::concurrent_test_3

pub fn concurrent_test_3(
    f1: impl FnOnce() + Send, 
    f2: impl FnOnce() + Send, 
    f3: impl FnOnce() + Send
)

Test that running three operations concurrently works

This is a variant of concurrent_test_2 that works with three functors instead of two. It is hoped that future evolutions of Rust will render this (light) code duplication obsolete, in favor of some variadic design.

Panics

This function will propagate panics from the inner functors.