tree-wide: Prefer core exports where possible

Don't make it harder than necessary to use no_std.

Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>

Author: amboar

examples/80211.rs

@@ -1,7 +1,7 @@
 use deku::ctx::Order;
 use deku::prelude::*;
 
-use std::convert::TryFrom;
+use core::convert::TryFrom;
 
 #[derive(Debug, DekuRead, DekuWrite, PartialEq)]
 #[deku(id_type = "u8", bits = "2")]

examples/custom_reader_and_writer.rs

@@ -1,4 +1,4 @@
-use std::convert::TryInto;
+use core::convert::TryInto;
 
 use deku::ctx::BitSize;
 use deku::writer::Writer;

examples/enums_catch_all.rs

@@ -1,4 +1,4 @@
-use std::convert::{TryFrom, TryInto};
+use core::convert::{TryFrom, TryInto};
 
 use deku::prelude::*;
 use hexlit::hex;

examples/example.rs

@@ -5,7 +5,7 @@
 
 #![allow(clippy::unusual_byte_groupings)]
 
-use std::convert::{TryFrom, TryInto};
+use core::convert::{TryFrom, TryInto};
 
 use deku::prelude::*;
 

examples/ipv4.rs

@@ -1,4 +1,4 @@
-use std::net::Ipv4Addr;
+use core::net::Ipv4Addr;
 
 use deku::prelude::*;
 use hexlit::hex;

examples/read_all.rs

@@ -1,5 +1,5 @@
+use core::convert::{TryFrom, TryInto};
 use deku::prelude::*;
-use std::convert::{TryFrom, TryInto};
 
 fn main() {
     #[derive(PartialEq, Debug, DekuRead, DekuWrite)]