Unwrap singleton block expressions in const arguments

This commit is contained in:
varkor 2019-05-11 00:08:19 +01:00
parent cff1bdbd77
commit 0686daab4e

View File

@ -1902,7 +1902,18 @@ impl<'o, 'gcx: 'tcx, 'tcx> dyn AstConv<'gcx, 'tcx> + 'o {
ty,
};
let expr = &tcx.hir().body(ast_const.body).value;
let mut expr = &tcx.hir().body(ast_const.body).value;
// Unwrap a block, so that e.g. `{ P }` is recognised as a parameter. Const arguments
// currently have to be wrapped in curly brackets, so it's necessary to special-case.
if let ExprKind::Block(block, _) = &expr.node {
if block.stmts.is_empty() {
if let Some(trailing) = &block.expr {
expr = &trailing;
}
}
}
if let ExprKind::Path(ref qpath) = expr.node {
if let hir::QPath::Resolved(_, ref path) = qpath {
if let Res::Def(DefKind::ConstParam, def_id) = path.res {