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const fn-ify std::any::type_name as laid out in #63084 #63123

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Merged
merged 2 commits into from
Jul 31, 2019
Merged

const fn-ify std::any::type_name as laid out in #63084 #63123

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873b361
Add a test for std::any::type_name() as a const fn
TankhouseAle Jul 30, 2019
4a3d41d
Add the necessary changes to any.rs
TankhouseAle Jul 30, 2019
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3 changes: 2 additions & 1 deletion src/libcore/any.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -468,7 +468,8 @@ impl TypeId {
/// The current implementation uses the same infrastructure as compiler
/// diagnostics and debuginfo, but this is not guaranteed.
#[stable(feature = "type_name", since = "1.38.0")]
pub fn type_name<T: ?Sized>() -> &'static str {
#[rustc_const_unstable(feature = "const_type_name")]
pub const fn type_name<T: ?Sized>() -> &'static str {
#[cfg(bootstrap)]
unsafe {
intrinsics::type_name::<T>()
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29 changes: 29 additions & 0 deletions src/test/ui/consts/const-fn-type-name-any.rs
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@@ -0,0 +1,29 @@
// run-pass

#![feature(const_fn)]
#![feature(const_type_name)]
#![allow(dead_code)]

const fn type_name_wrapper<T>(_: &T) -> &'static str {
std::any::type_name::<T>()
}

struct Struct<TA, TB, TC> {
a: TA,
b: TB,
c: TC,
}

type StructInstantiation = Struct<i8, f64, bool>;

const CONST_STRUCT: StructInstantiation = StructInstantiation { a: 12, b: 13.7, c: false };

const CONST_STRUCT_NAME: &'static str = type_name_wrapper(&CONST_STRUCT);

fn main() {
let non_const_struct = StructInstantiation { a: 87, b: 65.99, c: true };

let non_const_struct_name = type_name_wrapper(&non_const_struct);

assert_eq!(CONST_STRUCT_NAME, non_const_struct_name);
}