assign a Closure in Enum

[ulinlong]

Compiler say it's a bug :note: the compiler unexpectedly panicked. this is a bug.

I tried this code:

fn main() {
    
    let x:i32 = 0;

    let square = Functions::Square;

    println!("x square is {}", square(x));

}

enum Functions{
    Square = |x:i32|{x*x},
}

Meta

 Compiling advanced_function v0.1.0 (file:///C:/Users/tt/IdeaProjects/advanced_function)
error: internal compiler error: src\librustc_typeck\check\mod.rs:820: can't type-check body of DefId(0/0:4 ~ advanced_function[1c36]::Functions[0])
  --> src\main.rs:13:1
   |
13 | / enum Functions{
14 | |     Square = |x:i32|{x*x},
15 | | }
   | |_^

note: the compiler unexpectedly panicked. this is a bug.

note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports

note: rustc 1.24.1 (d3ae9a9e0 2018-02-27) running on x86_64-pc-windows-msvc

note: run with `RUST_BACKTRACE=1` for a backtrace

thread 'rustc' panicked at 'Box<Any>', src\librustc_errors\lib.rs:451:9
stack backtrace:
   0: <std::sync::condvar::WaitTimeoutResult as core::fmt::Debug>::fmt
   1: <std::time::SystemTimeError as core::fmt::Display>::fmt
   2: std::panicking::Location::column
   3: std::panicking::Location::column
   4: std::panicking::rust_panic_with_hook
   5: <rustc_typeck::check::method::probe::ProbeScope as core::fmt::Debug>::fmt
   6: <rustc_typeck::constrained_type_params::Parameter as core::fmt::Debug>::fmt
   7: <rustc::hir::Arm as rustc_typeck::check::coercion::AsCoercionSite>::as_coercion_site
   8: <rustc_typeck::check::upvar::InferBorrowKindVisitor<'a, 'gcx, 'tcx> as rustc::hir::intravisit::Visitor<'gcx>>::nested_visit_map
   9: <rustc_typeck::check::op::Op as core::fmt::Debug>::fmt
  10: <rustc_typeck::check::CheckItemTypesVisitor<'a, 'tcx> as rustc::hir::itemlikevisit::ItemLikeVisitor<'tcx>>::visit_item
  11: rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_tables_of<'tcx>>::ensure
  12: rustc::dep_graph::graph::DepGraph::in_ignore
  13: rustc::util::ppaux::<impl core::fmt::Debug for rustc::ty::Predicate<'tcx>>::fmt
  14: <rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx> as rustc::ty::layout::HasTyCtxt<'gcx>>::tcx
  15: rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_tables_of<'tcx>>::ensure
  16: rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_tables_of<'tcx>>::try_get
  17: rustc::ty::maps::TyCtxtAt::typeck_tables_of
  18: rustc::ty::maps::<impl rustc::ty::context::TyCtxt<'a, 'tcx, 'lcx>>::typeck_tables_of
  19: <rustc_typeck::check::CheckItemTypesVisitor<'a, 'tcx> as rustc::hir::itemlikevisit::ItemLikeVisitor<'tcx>>::visit_item
  20: rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_tables_of<'tcx>>::ensure
  21: rustc::dep_graph::graph::DepGraph::in_ignore
  22: rustc::util::ppaux::<impl core::fmt::Debug for rustc::ty::Predicate<'tcx>>::fmt
  23: <rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx> as rustc::ty::layout::HasTyCtxt<'gcx>>::tcx
  24: rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_tables_of<'tcx>>::ensure
  25: rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_tables_of<'tcx>>::try_get
  26: rustc::ty::maps::TyCtxtAt::typeck_tables_of
  27: rustc::ty::maps::<impl rustc::ty::context::TyCtxt<'a, 'tcx, 'lcx>>::typeck_tables_of
  28: rustc_mir::interpret::const_eval::const_eval_provider
  29: rustc::ty::maps::<impl rustc::ty::maps::queries::const_eval<'tcx>>::ensure
  30: rustc::dep_graph::graph::DepGraph::in_ignore
  31: rustc::util::ppaux::<impl core::fmt::Debug for rustc::ty::Predicate<'tcx>>::fmt
  32: <rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx> as rustc::ty::layout::HasTyCtxt<'gcx>>::tcx
  33: rustc::ty::maps::<impl rustc::ty::maps::queries::const_eval<'tcx>>::ensure
  34: rustc::ty::maps::<impl rustc::ty::maps::queries::const_eval<'tcx>>::try_get
  35: rustc::ty::maps::TyCtxtAt::const_eval
  36: <rustc_typeck::collect::CollectItemTypesVisitor<'a, 'tcx> as rustc::hir::intravisit::Visitor<'tcx>>::visit_item
  37: <unknown>
  38: rustc_typeck::check_crate
  39: rustc_driver::profile::dump
  40: rustc_driver::profile::dump
  41: <rustc_driver::Compilation as core::fmt::Debug>::fmt
  42: rustc_driver::driver::compile_input
  43: rustc_driver::run_compiler
  44: rustc_driver::profile::dump
  45: _rust_maybe_catch_panic
  46: <rustc_driver::pretty::UserIdentifiedItem as core::fmt::Debug>::fmt
  47: <std::sync::condvar::Condvar as core::fmt::Debug>::fmt
  48: std::sys::windows::thread::Thread::new
  49: BaseThreadInitThunk

error: Could not compile `advanced_function`.

To learn more, run the command again with --verbose.

Process finished with exit code 101

[Centril]

Minimal reproducing example

#![crate_type = "rlib"]

enum Functions {
    Square = |x| x,
}