[Rust] Show the boundary of various number types

// Call related modules in standard library
use std::{i8, i16, i32, i64, isize};
use std::{u8, u16, u32, u64, usize};
use std::{f32, f64};

fn main() {
    // signed, fixed-width integers
    println!("i8 min: {}, max: {}", i8::min_value(), i8::max_value());
    println!("i16 min: {}, max: {}", i16::min_value(), i16::max_value());
    println!("i32 min: {}, max: {}", i32::min_value(), i32::max_value());
    println!("i64 min: {}, max: {}", i64::min_value(), i64::max_value());

    // unsigned, fixed-width integers
    println!("u8 min: {}, max: {}", u8::min_value(), u8::max_value());
    println!("u16 min: {}, max: {}", u16::min_value(), u16::max_value());
    println!("u32 min: {}, max: {}", u32::min_value(), u32::max_value());
    println!("u64 min: {}, max: {}", u64::min_value(), u64::max_value());

    // variable-width integers (platform dependant)
    println!("isize min: {}, max: {}",
             isize::min_value(),
             isize::max_value());
    println!("usize min: {}, max: {}",
             usize::min_value(),
             usize::max_value());

    // floating point numbers
    println!("f32 min: {}, max: {}, min positive: {}",
             f32::MIN,
             f32::MAX,
             f32::MIN_POSITIVE);
    println!("f64 min: {}, max: {}, min positive: {}",
             f64::MIN,
             f64::MAX,
             f64::MIN_POSITIVE);
}