We can simply read user input in C++ or Python Ex (for C++): std::cin >> name; Ex (for Python): name = input("Your name: ") But, in Rust we have to use that "things" use std::io; use std::io::*; fn main() { let mut input = String::new(); io::stdin::().read_line(&mut input).expect(“er…

I think comparing the error handling cases is the right thing to do. Because in an interactive program, ignoring failures (which cin >> does by default) is always the wrong thing. Okay, it's fine in toy programs, maybe, but for anything even remotely serious? You can't just turn anything that isn't …

One way to look at it is that Rust doesn't focus on small programs with simple problems. It handles problems that arise in bigger, more complex programs. For example, instead of String::new() you have an option of using String::with_capacity(…) to pre-allocate the expected size of the buffer, for e…

Your C++ example is far from complete. The equivalent Rust code would be std::io::stdin().read_line(&mut name)?; Which, compared to std::cin >> name; is not that bad. Now, more generally, this is where low level language vs high level language comes into play: a function like Python3's input fu…

The full C++ code, which would do the same as the Rust example, would be: #include <iostream> #include <string> int main() { std::string name {}; std::cin >> name; std::cout << name << '\n'; return 0; } Now, I don't see how Rust is so bad. You can write a Rust function to return…

It's suprising how little I find need to get user input. For me, it's almost always easier to have some sort of config format e.g. toml and then use serde to read the data in. Having said that I did make some functions to get data of the user. I'm on the wrong computer or else I'd post them. They u…

I think one of the things that create friction for beginners and boilerplate in rust is actually one of the strong points of rust. Yes, C++ will let your write fallible code without having to handle the potential errors. In rust you can't ignore their existence. It also means you don't have to figu…

First off, I agree with you that C++'s std::cin can hide the fact that it failed from you. You don't have to handle a potential error for your code to compile. This is something where I agree that Rust is better. However, you can feed std::cin a lot of different data types. In Rust, getting integer…

I rarely use stdin, so I'm not the best placed here, but in any case it implements std::io::Read , which is more generic than just read_line. You can read into a &mut [u8], which means you can then convert the contents of that into your type. Unfortunately, I think creating integers from a byte buffe…

I am not sure how all that stuff works behind the scenes. I just know that I have this minor nitpick with Rust that I have to do this: use std::io; let mut x = String::new(); io::stdin().read_line(&mut x).expect("Failed to get console input"); let x = x.trim().parse<i32>::().expect("Failed to parse…

No, .read_i32::<LE>() reads 4 bytes from stdin, transmute() it to i32, and .from_le() on it. It does not care about ascii integer at all.

Well, this still raises the question: why the need to allocate a String first? Can't you have all the error checking and all the other niceties of Rust, but operate directly from stdin to your i32 or bool? Doesn't it slow the program to have to allocate a second, unnecessary, intermediate buffer jus…

Why is it so difficult to get user input in Rust?

help

derekdreery April 26, 2019, 1:42pm 14

Right I made my code into a library to do this, called read-human. Hope it's useful.

EDIT wrong name duh

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Why is it so difficult to get user input in Rust?

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