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Remove 1-argument special case from format_args!().

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The argument needs to be lifetime-extended, so this special case isn't
actually perfectly equivalent to the general case.
This commit is contained in:
Mara Bos 2025-08-26 14:44:41 +02:00
parent 5fb947f650
commit aa9c8ceb73
1 changed files with 0 additions and 20 deletions
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20
compiler/rustc_ast_lowering/src/format.rs
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@ -487,26 +487,6 @@ fn expand_format_args<'hir>(
// Generate:
// []
(vec![], ctx.arena.alloc(ctx.expr(macsp, hir::ExprKind::Array(&[]))))
} else if argmap.len() == 1 && arguments.len() == 1 {
// Only one argument, so we don't need to make the `args` tuple.
//
// Generate:
// super let args = [<core::fmt::Argument>::new_display(&arg)];
let args = ctx.arena.alloc_from_iter(argmap.iter().map(
|(&(arg_index, ty), &placeholder_span)| {
let arg = &arguments[arg_index];
let placeholder_span =
placeholder_span.unwrap_or(arg.expr.span).with_ctxt(macsp.ctxt());
let arg = ctx.lower_expr(&arg.expr);
let ref_arg = ctx.arena.alloc(ctx.expr_ref(arg.span.with_ctxt(macsp.ctxt()), arg));
make_argument(ctx, placeholder_span, ref_arg, ty)
},
));
let args = ctx.arena.alloc(ctx.expr(macsp, hir::ExprKind::Array(args)));
let args_ident = Ident::new(sym::args, macsp);
let (args_pat, args_hir_id) = ctx.pat_ident(macsp, args_ident);
let let_statement = ctx.stmt_super_let_pat(macsp, args_pat, Some(args));
(vec![let_statement], ctx.arena.alloc(ctx.expr_ident_mut(macsp, args_ident, args_hir_id)))
} else {
// Generate:
// super let args = (&arg0, &arg1, &…);