1 unstable release
0.0.3 | Sep 24, 2023 |
---|---|
0.0.2 |
|
0.0.1 |
|
0.0.0 |
|
#2451 in Rust patterns
536 downloads per month
6KB
A crate that allows you to mostly-safely cast one type into another type.
This is mostly useful for generic functions, e.g.
pub fn foo<S>(s: S) {
if let Ok(a) = unsafe { unty::<S, u8>(s) } {
println!("It is an u8 with value {a}");
} else {
println!("it is not an u8");
}
}
foo(10u8); // will print "it is an u8"
foo("test"); // will print "it is not an u8"
This operation is still unsafe because it allows you to extend lifetimes. There currently is not a way to prevent this
if let Ok(str) = unsafe { unty::<&'a str, &'static str>(input) } {
// the compiler may now light your PC on fire
}
License
This crate is dual licenced MIT and Apache-2.0, at your own leisure
lib.rs
:
A crate that allows you to untype your types.
This provides 2 functions:
type_equal
allows you to check if two types are the same.
unty
allows you to downcast a generic type into a concrete type.
This is mostly useful for generic functions, e.g.
pub fn foo<S>(s: S) {
if let Ok(a) = unsafe { unty::<S, u8>(s) } {
println!("It is an u8 with value {a}");
} else {
println!("it is not an u8");
}
}
foo(10u8); // will print "it is an u8"
foo("test"); // will print "it is not an u8"
Note that both of these functions may give false positives if both types have lifetimes. There currently is not a way to prevent this. See type_equal
for more information.
assert!(type_equal::<&'a str, &'static str>()); // these are not actually the same
if let Ok(str) = unsafe { unty::<&'a str, &'static str>(input) } {
// this will extend the &'a str lifetime to be &'static, which is not allowed.
// the compiler may now light your PC on fire.
}