auto merge of #19027 : nick29581/rust/coercions-4, r=alexcrichton

The forwards compatible parts of #18645, rebased. Converts implicit coercions from `[T, ..n]` to `&[T]` into explicit references.

2 files changed, 6 insertions, 6 deletions

diff --git a/src/libsyntax/ext/deriving/decodable.rs b/src/libsyntax/ext/deriving/decodable.rs
index fd24f5e35a4..9e4dbf930db 100644
--- a/src/libsyntax/ext/deriving/decodable.rs
+++ b/src/libsyntax/ext/deriving/decodable.rs
@@ -136,6 +136,7 @@ fn decodable_substructure(cx: &mut ExtCtxt, trait_span: Span,
                                                   cx.expr_ident(trait_span, variant), arms));
             let lambda = cx.lambda_expr(trait_span, vec!(blkarg, variant), result);
             let variant_vec = cx.expr_vec(trait_span, variants);
+            let variant_vec = cx.expr_addr_of(trait_span, variant_vec);
             let result = cx.expr_method_call(trait_span, blkdecoder,
                                              cx.ident_of("read_enum_variant"),
                                              vec!(variant_vec, lambda));
diff --git a/src/libsyntax/ext/format.rs b/src/libsyntax/ext/format.rs
index a816b479630..d4248a2c77d 100644
--- a/src/libsyntax/ext/format.rs
+++ b/src/libsyntax/ext/format.rs
@@ -14,7 +14,7 @@ use ext::base::*;
 use ext::base;
 use ext::build::AstBuilder;
 use fmt_macros as parse;
-use parse::token::InternedString;
+use parse::token::{InternedString, special_idents};
 use parse::token;
 use ptr::P;
 
@@ -476,12 +476,11 @@ impl<'a, 'b> Context<'a, 'b> {
                          pieces: Vec<P<ast::Expr>>)
                          -> P<ast::Stmt> {
         let fmtsp = piece_ty.span;
-        let pieces_len = ecx.expr_uint(fmtsp, pieces.len());
         let fmt = ecx.expr_vec(fmtsp, pieces);
-        let ty = ast::TyFixedLengthVec(
-            piece_ty,
-            pieces_len
-        );
+        let fmt = ecx.expr_addr_of(fmtsp, fmt);
+        let ty = ast::TyVec(piece_ty);
+        let ty = ast::TyRptr(Some(ecx.lifetime(fmtsp, special_idents::static_lifetime.name)),
+                             ast::MutTy{ mutbl: ast::MutImmutable, ty: ecx.ty(fmtsp, ty) });
         let ty = ecx.ty(fmtsp, ty);
         let st = ast::ItemStatic(ty, ast::MutImmutable, fmt);
         let item = ecx.item(fmtsp, name, Context::static_attrs(ecx, fmtsp), st);