From f79bf19a7a9dc9bbdab3d1c274bd267b0e86a66e Mon Sep 17 00:00:00 2001 From: Boxy Date: Sun, 30 Jun 2024 15:15:05 +0100 Subject: [PATCH] Update test comment --- .../repeat_expr_hack_gives_right_generics.rs | 22 +++++++++++-------- ...peat_expr_hack_gives_right_generics.stderr | 2 +- 2 files changed, 14 insertions(+), 10 deletions(-) diff --git a/tests/ui/const-generics/repeat_expr_hack_gives_right_generics.rs b/tests/ui/const-generics/repeat_expr_hack_gives_right_generics.rs index 899db191ae7..e7ae2ea1d5a 100644 --- a/tests/ui/const-generics/repeat_expr_hack_gives_right_generics.rs +++ b/tests/ui/const-generics/repeat_expr_hack_gives_right_generics.rs @@ -1,14 +1,18 @@ -// Given an anon const `a`: `{ N }` and some anon const `b` which references the -// first anon const: `{ [1; a] }`. `b` should not have any generics as it is not -// a simple `N` argument nor is it a repeat expr count. +// Given a const argument `a`: `{ N }` and some const argument `b` which references the +// first anon const like so: `{ [1; a] }`. The `b` anon const should not be allowed to use +// any generic parameters as: +// - The anon const is not a simple bare parameter, e.g. `N` +// - The anon const is not the *length* of an array repeat expression, e.g. the `N` in `[1; N]`. // -// On the other hand `b` *is* a repeat expr count and so it should inherit its -// parents generics as part of the `const_evaluatable_unchecked` fcw (#76200). +// On the other hand `a` *is* a const argument for the length of a repeat expression and +// so it *should* inherit the generics declared on its parent definition. (This hack is +// introduced for backwards compatibility and is tracked in #76200) // -// In this specific case however `b`'s parent should be `a` and so it should wind -// up not having any generics after all. If `a` were to inherit its generics from -// the enclosing item then the reference to `a` from `b` would contain generic -// parameters not usable by `b` which would cause us to ICE. +// In this specific case `a`'s parent should be `b` which does not have any generics. +// This means that even though `a` inherits generics from `b`, it still winds up not having +// access to any generic parameters. If `a` were to inherit its generics from the surrounding +// function `foo` then the reference to `a` from `b` would contain generic parameters not usable +// by `b` which would cause us to ICE. fn bar() {} diff --git a/tests/ui/const-generics/repeat_expr_hack_gives_right_generics.stderr b/tests/ui/const-generics/repeat_expr_hack_gives_right_generics.stderr index 64548cc5a30..72a6e6977f5 100644 --- a/tests/ui/const-generics/repeat_expr_hack_gives_right_generics.stderr +++ b/tests/ui/const-generics/repeat_expr_hack_gives_right_generics.stderr @@ -1,5 +1,5 @@ error: generic parameters may not be used in const operations - --> $DIR/repeat_expr_hack_gives_right_generics.rs:16:17 + --> $DIR/repeat_expr_hack_gives_right_generics.rs:20:17 | LL | bar::<{ [1; N] }>(); | ^ cannot perform const operation using `N`