diff options
Diffstat (limited to 'src/libsyntax/ext')
| -rw-r--r-- | src/libsyntax/ext/deriving/encodable.rs | 37 |
1 files changed, 18 insertions, 19 deletions
diff --git a/src/libsyntax/ext/deriving/encodable.rs b/src/libsyntax/ext/deriving/encodable.rs index 8038074cee1..94b7d1b4d8c 100644 --- a/src/libsyntax/ext/deriving/encodable.rs +++ b/src/libsyntax/ext/deriving/encodable.rs @@ -240,25 +240,24 @@ fn encodable_substructure(cx: &mut ExtCtxt, trait_span: Span, let encoder = cx.expr_ident(trait_span, blkarg); let emit_variant_arg = cx.ident_of("emit_enum_variant_arg"); let mut stmts = Vec::new(); - let last = fields.len() - 1; - for (i, &FieldInfo { ref self_, span, .. }) in fields.iter().enumerate() { - let enc = cx.expr_method_call(span, self_.clone(), - encode, vec!(blkencoder.clone())); - let lambda = cx.lambda_expr_1(span, enc, blkarg); - let call = cx.expr_method_call(span, blkencoder.clone(), - emit_variant_arg, - vec!(cx.expr_usize(span, i), - lambda)); - let call = if i != last { - cx.expr_try(span, call) - } else { - cx.expr(span, ExprRet(Some(call))) - }; - stmts.push(cx.stmt_expr(call)); - } - - // enums with no fields need to return Ok() - if stmts.len() == 0 { + if fields.len() > 0 { + let last = fields.len() - 1; + for (i, &FieldInfo { ref self_, span, .. }) in fields.iter().enumerate() { + let enc = cx.expr_method_call(span, self_.clone(), + encode, vec!(blkencoder.clone())); + let lambda = cx.lambda_expr_1(span, enc, blkarg); + let call = cx.expr_method_call(span, blkencoder.clone(), + emit_variant_arg, + vec!(cx.expr_usize(span, i), + lambda)); + let call = if i != last { + cx.expr_try(span, call) + } else { + cx.expr(span, ExprRet(Some(call))) + }; + stmts.push(cx.stmt_expr(call)); + } + } else { let ret_ok = cx.expr(trait_span, ExprRet(Some(cx.expr_ok(trait_span, cx.expr_tuple(trait_span, vec![]))))); |