Function is_const_stable_const_fn

pub fn is_const_stable_const_fn(tcx: TyCtxt<'_>, def_id: DefId) -> bool

Returns true if the given const fn is “const-stable”.

Panics if the given DefId does not refer to a const fn.

Const-stability is only relevant for const fn within a staged_api crate. Only “const-stable” functions can be called in a const-context by users of the stable compiler. “const-stable” functions are subject to more stringent restrictions than “const-unstable” functions: They cannot use unstable features and can only call other “const-stable” functions.