Library for strings of fixed maximum lengths that can be copied and
stack-allocated. Certain provided
types such as `zstr<8>` and `str8` are smaller in size than a &str on
typical systems.
**Starting in Version 0.4.0, this crate supports `#![no_std]`, although
this feature is not enabled by default.** Giving cargo the
`--no-default-features` option will enable `no_std` and provide only the
zstr and tstr types with some reduced functionality.
<br>
Recent improvements also include a `Flexstr` type that uses an
internal enum that can be either a fixed-capacity string or an owned
String.
#### Examples
```
let a:str8 = str8::from("abcdef"); //a str8 can hold up to 7 bytes
let a2 = a; // copied, not moved
let ab = a.substr(1,5); // copies substring to new string
assert_eq!(ab, "bcde"); // can compare for equality with &str
assert_eq!(ab.len(),4);
println!("str8: {}", &a); // impls Display
assert_eq!(&a[..3], "abc"); // impls Index for Range types
assert!(a<ab); // and Ord, Hash, Debug, Eq, other common traits
let astr:&str = a.to_str(); // convert to &str (zero copy)
let aowned:String = a.to_string(); // convert to owned string
let afstr:fstr<8> = fstr::from(a); // fstr is another fixedstr crate type
let azstr:zstr<16> = zstr::from(a); // so is zstr
let a32:str32 = a.resize(); // same kind of string but with 31-byte capacity
let mut u = str8::from("aλb"); //unicode support
assert_eq!(u.nth(1), Some('λ')); // get nth character
assert_eq!(u.nth_ascii(3), 'b'); // get nth byte as ascii character
assert!(u.set(1,'μ')); // changes a character of the same character class
assert!(!u.set(1,'c')); // .set returns false on failure
assert!(u.set(2,'c'));
assert_eq!(u, "aμc");
assert_eq!(u.len(),4); // length in bytes
assert_eq!(u.charlen(),3); // length in chars
let mut ac:str16 = a.reallocate().unwrap(); //copies to larger capacity type
let remainder = ac.push("ghijklmnopq"); //append up to capacity, returns remainder
assert_eq!(ac.len(),15);
assert_eq!(remainder, "pq");
ac.truncate(9); // keep first 9 chars
assert_eq!(&ac,"abcdefghi");
let (upper,lower) = (str8::make("ABC"), str8::make("abc"));
assert_eq!(upper, lower.to_ascii_upper()); // no owned String needed
let c1 = str8::from("abcd"); // string concatenation with + for strN types
let c2 = str8::from("xyz");
let c3 = c1 + c2;
assert_eq!(c3,"abcdxyz");
assert_eq!(c3.capacity(),15); // type of c3 is str16
let c4 = str_format!(str16,"abc {}{}{}",1,2,3); // impls std::fmt::Write
assert_eq!(c4,"abc 123"); //str_format! truncates if capacity exceeded
let c5 = try_format!(str8,"abcdef{}","ghijklmn");
assert!(c5.is_none()); // try_format! returns None if capacity exceeded
```
Consult the [documentation](https://docs.rs/fixedstr/latest/fixedstr/) for details.