From 59c8a279daf6912b99ba089ff6dafbfc3469831e Mon Sep 17 00:00:00 2001 From: ljedrz Date: Thu, 26 Jul 2018 17:11:10 +0200 Subject: [PATCH] Replace push loops with collect() and extend() where possible --- src/bootstrap/util.rs | 5 +-- src/librustc/cfg/construct.rs | 10 +++--- src/librustc/infer/outlives/obligations.rs | 11 +++---- src/librustc/middle/reachable.rs | 8 ++--- src/librustc/mir/traversal.rs | 4 +-- src/librustc/session/config.rs | 4 +-- src/librustc/traits/specialize/mod.rs | 6 ++-- src/librustc_codegen_llvm/back/rpath.rs | 4 +-- .../debuginfo/metadata.rs | 23 +++++++------ src/librustc_codegen_llvm/debuginfo/mod.rs | 7 ++-- src/librustc_driver/lib.rs | 5 +-- src/librustc_driver/profile/trace.rs | 7 ++-- src/librustc_llvm/lib.rs | 6 +--- src/librustc_mir/transform/inline.rs | 7 ++-- src/librustc_resolve/lib.rs | 6 ++-- src/librustc_save_analysis/dump_visitor.rs | 11 +++---- src/librustc_typeck/collect.rs | 33 +++++++++---------- src/librustdoc/core.rs | 4 +-- src/librustdoc/lib.rs | 4 +-- src/libserialize/json.rs | 12 ++----- src/libstd/sys/redox/process.rs | 11 ++++--- src/libstd/sys/windows/process.rs | 8 ++--- src/libsyntax/ast.rs | 10 ++---- src/libsyntax/parse/lexer/mod.rs | 4 +-- src/libsyntax_ext/deriving/decodable.rs | 4 +-- src/libsyntax_ext/deriving/generic/mod.rs | 17 +++++----- src/libsyntax_ext/deriving/hash.rs | 5 ++- src/libsyntax_ext/format.rs | 15 ++++----- 28 files changed, 101 insertions(+), 150 deletions(-) diff --git a/src/bootstrap/util.rs b/src/bootstrap/util.rs index 9a2b9e90440e5..be03796921af8 100644 --- a/src/bootstrap/util.rs +++ b/src/bootstrap/util.rs @@ -92,10 +92,7 @@ pub fn push_exe_path(mut buf: PathBuf, components: &[&str]) -> PathBuf { file.push_str(".exe"); } - for c in components { - buf.push(c); - } - + buf.extend(components); buf.push(file); buf diff --git a/src/librustc/cfg/construct.rs b/src/librustc/cfg/construct.rs index f1e2794691556..98cfa094c169a 100644 --- a/src/librustc/cfg/construct.rs +++ b/src/librustc/cfg/construct.rs @@ -567,12 +567,12 @@ impl<'a, 'tcx> CFGBuilder<'a, 'tcx> { fn add_returning_edge(&mut self, _from_expr: &hir::Expr, from_index: CFGIndex) { - let mut data = CFGEdgeData { - exiting_scopes: vec![], + let data = CFGEdgeData { + exiting_scopes: self.loop_scopes.iter() + .rev() + .map(|&LoopScope { loop_id: id, .. }| id) + .collect() }; - for &LoopScope { loop_id: id, .. } in self.loop_scopes.iter().rev() { - data.exiting_scopes.push(id); - } self.graph.add_edge(from_index, self.fn_exit, data); } diff --git a/src/librustc/infer/outlives/obligations.rs b/src/librustc/infer/outlives/obligations.rs index b8991a0366a61..c74783f5e4db5 100644 --- a/src/librustc/infer/outlives/obligations.rs +++ b/src/librustc/infer/outlives/obligations.rs @@ -151,13 +151,12 @@ impl<'cx, 'gcx, 'tcx> InferCtxt<'cx, 'gcx, 'tcx> { debug!("process_registered_region_obligations()"); // pull out the region obligations with the given `body_id` (leaving the rest) - let mut my_region_obligations = Vec::with_capacity(self.region_obligations.borrow().len()); - { + let my_region_obligations = { let mut r_o = self.region_obligations.borrow_mut(); - for (_, obligation) in r_o.drain_filter(|(ro_body_id, _)| *ro_body_id == body_id) { - my_region_obligations.push(obligation); - } - } + let my_r_o = r_o.drain_filter(|(ro_body_id, _)| *ro_body_id == body_id) + .map(|(_, obligation)| obligation).collect::>(); + my_r_o + }; let outlives = &mut TypeOutlives::new( self, diff --git a/src/librustc/middle/reachable.rs b/src/librustc/middle/reachable.rs index 7f4b0bb126bbe..19c82d7d27c79 100644 --- a/src/librustc/middle/reachable.rs +++ b/src/librustc/middle/reachable.rs @@ -367,9 +367,7 @@ impl<'a, 'tcx: 'a> ItemLikeVisitor<'tcx> for CollectPrivateImplItemsVisitor<'a, // We need only trait impls here, not inherent impls, and only non-exported ones if let hir::ItemKind::Impl(.., Some(ref trait_ref), _, ref impl_item_refs) = item.node { if !self.access_levels.is_reachable(item.id) { - for impl_item_ref in impl_item_refs { - self.worklist.push(impl_item_ref.id.node_id); - } + self.worklist.extend(impl_item_refs.iter().map(|r| r.id.node_id)); let trait_def_id = match trait_ref.path.def { Def::Trait(def_id) => def_id, @@ -426,9 +424,7 @@ fn reachable_set<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, crate_num: CrateNum) -> // If other crates link to us, they're going to expect to be able to // use the lang items, so we need to be sure to mark them as // exported. - for (id, _) in &access_levels.map { - reachable_context.worklist.push(*id); - } + reachable_context.worklist.extend(access_levels.map.iter().map(|(id, _)| *id)); for item in tcx.lang_items().items().iter() { if let Some(did) = *item { if let Some(node_id) = tcx.hir.as_local_node_id(did) { diff --git a/src/librustc/mir/traversal.rs b/src/librustc/mir/traversal.rs index 87ba3420eeceb..86fd825850fc5 100644 --- a/src/librustc/mir/traversal.rs +++ b/src/librustc/mir/traversal.rs @@ -64,9 +64,7 @@ impl<'a, 'tcx> Iterator for Preorder<'a, 'tcx> { let data = &self.mir[idx]; if let Some(ref term) = data.terminator { - for &succ in term.successors() { - self.worklist.push(succ); - } + self.worklist.extend(term.successors()); } return Some((idx, data)); diff --git a/src/librustc/session/config.rs b/src/librustc/session/config.rs index 8f3ed3106d586..e0532a3320bc4 100644 --- a/src/librustc/session/config.rs +++ b/src/librustc/session/config.rs @@ -899,9 +899,7 @@ macro_rules! options { -> bool { match v { Some(s) => { - for s in s.split_whitespace() { - slot.push(s.to_string()); - } + slot.extend(s.split_whitespace().map(|s| s.to_string())); true }, None => false, diff --git a/src/librustc/traits/specialize/mod.rs b/src/librustc/traits/specialize/mod.rs index f151f3b2531a6..1ed9ae4392fa7 100644 --- a/src/librustc/traits/specialize/mod.rs +++ b/src/librustc/traits/specialize/mod.rs @@ -438,9 +438,9 @@ fn to_pretty_impl_header(tcx: TyCtxt, impl_def_id: DefId) -> Option { } pretty_predicates.push(p.to_string()); } - for ty in types_without_default_bounds { - pretty_predicates.push(format!("{}: ?Sized", ty)); - } + pretty_predicates.extend( + types_without_default_bounds.iter().map(|ty| format!("{}: ?Sized", ty)) + ); if !pretty_predicates.is_empty() { write!(w, "\n where {}", pretty_predicates.join(", ")).unwrap(); } diff --git a/src/librustc_codegen_llvm/back/rpath.rs b/src/librustc_codegen_llvm/back/rpath.rs index e73073cfad0c1..2c3a143646c24 100644 --- a/src/librustc_codegen_llvm/back/rpath.rs +++ b/src/librustc_codegen_llvm/back/rpath.rs @@ -152,9 +152,7 @@ fn path_relative_from(path: &Path, base: &Path) -> Option { (Some(_), Some(b)) if b == Component::ParentDir => return None, (Some(a), Some(_)) => { comps.push(Component::ParentDir); - for _ in itb { - comps.push(Component::ParentDir); - } + comps.extend(itb.map(|_| Component::ParentDir)); comps.push(a); comps.extend(ita.by_ref()); break; diff --git a/src/librustc_codegen_llvm/debuginfo/metadata.rs b/src/librustc_codegen_llvm/debuginfo/metadata.rs index 6d727f7b048c6..2f4dd5a7ce5bb 100644 --- a/src/librustc_codegen_llvm/debuginfo/metadata.rs +++ b/src/librustc_codegen_llvm/debuginfo/metadata.rs @@ -39,6 +39,7 @@ use rustc::util::common::path2cstr; use libc::{c_uint, c_longlong}; use std::ffi::CString; use std::fmt::Write; +use std::iter; use std::ptr; use std::path::{Path, PathBuf}; use syntax::ast; @@ -364,18 +365,16 @@ fn subroutine_type_metadata<'a, 'tcx>(cx: &CodegenCx<'a, 'tcx>, &signature, ); - let mut signature_metadata: Vec = Vec::with_capacity(signature.inputs().len() + 1); - - // return type - signature_metadata.push(match signature.output().sty { - ty::TyTuple(ref tys) if tys.is_empty() => ptr::null_mut(), - _ => type_metadata(cx, signature.output(), span) - }); - - // regular arguments - for &argument_type in signature.inputs() { - signature_metadata.push(type_metadata(cx, argument_type, span)); - } + let signature_metadata: Vec = iter::once( + // return type + match signature.output().sty { + ty::TyTuple(ref tys) if tys.is_empty() => ptr::null_mut(), + _ => type_metadata(cx, signature.output(), span) + } + ).chain( + // regular arguments + signature.inputs().iter().map(|argument_type| type_metadata(cx, argument_type, span)) + ).collect(); return_if_metadata_created_in_meantime!(cx, unique_type_id); diff --git a/src/librustc_codegen_llvm/debuginfo/mod.rs b/src/librustc_codegen_llvm/debuginfo/mod.rs index 068dd9821ac97..9671db75baffe 100644 --- a/src/librustc_codegen_llvm/debuginfo/mod.rs +++ b/src/librustc_codegen_llvm/debuginfo/mod.rs @@ -352,9 +352,10 @@ pub fn create_function_debug_context<'a, 'tcx>(cx: &CodegenCx<'a, 'tcx>, if sig.abi == Abi::RustCall && !sig.inputs().is_empty() { if let ty::TyTuple(args) = sig.inputs()[sig.inputs().len() - 1].sty { - for &argument_type in args { - signature.push(type_metadata(cx, argument_type, syntax_pos::DUMMY_SP)); - } + signature.extend( + args.iter().map(|argument_type| + type_metadata(cx, argument_type, syntax_pos::DUMMY_SP)) + ); } } diff --git a/src/librustc_driver/lib.rs b/src/librustc_driver/lib.rs index 29b9990de34eb..e25da0632c064 100644 --- a/src/librustc_driver/lib.rs +++ b/src/librustc_driver/lib.rs @@ -1588,10 +1588,7 @@ pub fn in_rustc_thread(f: F) -> Result> /// debugging, since some ICEs only happens with non-default compiler flags /// (and the users don't always report them). fn extra_compiler_flags() -> Option<(Vec, bool)> { - let mut args = Vec::new(); - for arg in env::args_os() { - args.push(arg.to_string_lossy().to_string()); - } + let args = env::args_os().map(|arg| arg.to_string_lossy().to_string()).collect::>(); // Avoid printing help because of empty args. This can suggest the compiler // itself is not the program root (consider RLS). diff --git a/src/librustc_driver/profile/trace.rs b/src/librustc_driver/profile/trace.rs index 797ed4505b44a..3d4f4b029e543 100644 --- a/src/librustc_driver/profile/trace.rs +++ b/src/librustc_driver/profile/trace.rs @@ -204,10 +204,9 @@ pub fn write_counts(count_file: &mut File, counts: &mut HashMap>(); data.sort_by_key(|k| Reverse(k.3)); for (cons, count, dur_total, dur_self) in data { write!(count_file, "{}, {}, {}, {}\n", diff --git a/src/librustc_llvm/lib.rs b/src/librustc_llvm/lib.rs index 741758cb954ba..91f9b4ac03b86 100644 --- a/src/librustc_llvm/lib.rs +++ b/src/librustc_llvm/lib.rs @@ -275,12 +275,8 @@ pub fn get_param(llfn: ValueRef, index: c_uint) -> ValueRef { fn get_params(llfn: ValueRef) -> Vec { unsafe { let num_params = LLVMCountParams(llfn); - let mut params = Vec::with_capacity(num_params as usize); - for idx in 0..num_params { - params.push(LLVMGetParam(llfn, idx)); - } - params + (0..num_params).map(|idx| LLVMGetParam(llfn, idx)).collect() } } diff --git a/src/librustc_mir/transform/inline.rs b/src/librustc_mir/transform/inline.rs index a0a5980d141dd..46fab544aafe9 100644 --- a/src/librustc_mir/transform/inline.rs +++ b/src/librustc_mir/transform/inline.rs @@ -406,10 +406,9 @@ impl<'a, 'tcx> Inliner<'a, 'tcx> { local_map.push(idx); } - for p in callee_mir.promoted.iter().cloned() { - let idx = caller_mir.promoted.push(p); - promoted_map.push(idx); - } + promoted_map.extend( + callee_mir.promoted.iter().cloned().map(|p| caller_mir.promoted.push(p)) + ); // If the call is something like `a[*i] = f(i)`, where // `i : &mut usize`, then just duplicating the `a[*i]` diff --git a/src/librustc_resolve/lib.rs b/src/librustc_resolve/lib.rs index 725b3b4f15034..b6f0ff291d48e 100644 --- a/src/librustc_resolve/lib.rs +++ b/src/librustc_resolve/lib.rs @@ -3831,9 +3831,9 @@ impl<'a> Resolver<'a> { } // Add primitive types to the mix if filter_fn(Def::PrimTy(TyBool)) { - for (name, _) in &self.primitive_type_table.primitive_types { - names.push(*name); - } + names.extend( + self.primitive_type_table.primitive_types.iter().map(|(name, _)| name) + ) } } else { // Search in module. diff --git a/src/librustc_save_analysis/dump_visitor.rs b/src/librustc_save_analysis/dump_visitor.rs index ac7085a55cfe0..04a4bca4ffbda 100644 --- a/src/librustc_save_analysis/dump_visitor.rs +++ b/src/librustc_save_analysis/dump_visitor.rs @@ -1318,14 +1318,13 @@ impl<'l, 'tcx: 'l, 'll, O: DumpOutput + 'll> DumpVisitor<'l, 'tcx, 'll, O> { }; // Make a comma-separated list of names of imported modules. - let mut names = vec![]; let glob_map = &self.save_ctxt.analysis.glob_map; let glob_map = glob_map.as_ref().unwrap(); - if glob_map.contains_key(&id) { - for n in glob_map.get(&id).unwrap() { - names.push(n.to_string()); - } - } + let names = if glob_map.contains_key(&id) { + glob_map.get(&id).unwrap().iter().map(|n| n.to_string()).collect() + } else { + Vec::new() + }; let sub_span = self.span.sub_span_of_token(use_tree.span, token::BinOp(token::Star)); diff --git a/src/librustc_typeck/collect.rs b/src/librustc_typeck/collect.rs index cd84a61bb2c35..77b02d9ff5bce 100644 --- a/src/librustc_typeck/collect.rs +++ b/src/librustc_typeck/collect.rs @@ -962,19 +962,21 @@ fn generics_of<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, &["", ""][..] }; - for (i, &arg) in dummy_args.iter().enumerate() { - params.push(ty::GenericParamDef { - index: type_start + i as u32, - name: Symbol::intern(arg).as_interned_str(), - def_id, - pure_wrt_drop: false, - kind: ty::GenericParamDefKind::Type { - has_default: false, - object_lifetime_default: rl::Set1::Empty, - synthetic: None, - }, - }); - } + params.extend( + dummy_args.iter().enumerate().map(|(i, &arg)| + ty::GenericParamDef { + index: type_start + i as u32, + name: Symbol::intern(arg).as_interned_str(), + def_id, + pure_wrt_drop: false, + kind: ty::GenericParamDefKind::Type { + has_default: false, + object_lifetime_default: rl::Set1::Empty, + synthetic: None, + }, + } + ) + ); tcx.with_freevars(node_id, |fv| { params.extend(fv.iter().zip((dummy_args.len() as u32)..).map(|(_, i)| { @@ -1651,10 +1653,7 @@ fn explicit_predicates_of<'a, 'tcx>( &mut projections); predicates.push(trait_ref.to_predicate()); - - for projection in &projections { - predicates.push(projection.to_predicate()); - } + predicates.extend(projections.iter().map(|p| p.to_predicate())); } &hir::GenericBound::Outlives(ref lifetime) => { diff --git a/src/librustdoc/core.rs b/src/librustdoc/core.rs index 77375442d4ce5..769c9804a355a 100644 --- a/src/librustdoc/core.rs +++ b/src/librustdoc/core.rs @@ -203,9 +203,7 @@ pub fn run_core(search_paths: SearchPaths, intra_link_resolution_failure_name.to_owned(), missing_docs.to_owned()]; - for (lint, _) in &cmd_lints { - whitelisted_lints.push(lint.clone()); - } + whitelisted_lints.extend(cmd_lints.iter().map(|(lint, _)| lint).cloned()); let lints = lint::builtin::HardwiredLints.get_lints() .into_iter() diff --git a/src/librustdoc/lib.rs b/src/librustdoc/lib.rs index 00cad5e376a40..613ca01ff82f8 100644 --- a/src/librustdoc/lib.rs +++ b/src/librustdoc/lib.rs @@ -722,9 +722,7 @@ where R: 'static + Send, }, _ => continue, }; - for p in value.as_str().split_whitespace() { - sink.push(p.to_string()); - } + sink.extend(value.as_str().split_whitespace().map(|p| p.to_string())); } if attr.is_word() && name == Some("document_private_items") { diff --git a/src/libserialize/json.rs b/src/libserialize/json.rs index 88cc93731131d..b5986e88b6645 100644 --- a/src/libserialize/json.rs +++ b/src/libserialize/json.rs @@ -1364,9 +1364,7 @@ impl Stack { // Used by Parser to insert StackElement::Key elements at the top of the stack. fn push_key(&mut self, key: string::String) { self.stack.push(InternalKey(self.str_buffer.len() as u16, key.len() as u16)); - for c in key.as_bytes() { - self.str_buffer.push(*c); - } + self.str_buffer.extend(key.as_bytes()); } // Used by Parser to insert StackElement::Index elements at the top of the stack. @@ -2212,9 +2210,7 @@ impl ::Decoder for Decoder { }; match o.remove(&"fields".to_string()) { Some(Json::Array(l)) => { - for field in l.into_iter().rev() { - self.stack.push(field); - } + self.stack.extend(l.into_iter().rev()); }, Some(val) => { return Err(ExpectedError("Array".to_owned(), format!("{}", val))) @@ -2346,9 +2342,7 @@ impl ::Decoder for Decoder { { let array = expect!(self.pop(), Array)?; let len = array.len(); - for v in array.into_iter().rev() { - self.stack.push(v); - } + self.stack.extend(array.into_iter().rev()); f(self, len) } diff --git a/src/libstd/sys/redox/process.rs b/src/libstd/sys/redox/process.rs index 02bc467541eca..2037616e6ac7c 100644 --- a/src/libstd/sys/redox/process.rs +++ b/src/libstd/sys/redox/process.rs @@ -13,6 +13,7 @@ use ffi::OsStr; use os::unix::ffi::OsStrExt; use fmt; use io::{self, Error, ErrorKind}; +use iter; use libc::{EXIT_SUCCESS, EXIT_FAILURE}; use path::{Path, PathBuf}; use sys::fd::FileDesc; @@ -296,11 +297,11 @@ impl Command { t!(callback()); } - let mut args: Vec<[usize; 2]> = Vec::new(); - args.push([self.program.as_ptr() as usize, self.program.len()]); - for arg in self.args.iter() { - args.push([arg.as_ptr() as usize, arg.len()]); - } + let args: Vec<[usize; 2]> = iter::once( + [self.program.as_ptr() as usize, self.program.len()] + ).chain( + self.args.iter().map(|arg| [arg.as_ptr() as usize, arg.len()]) + ).collect(); self.env.apply(); diff --git a/src/libstd/sys/windows/process.rs b/src/libstd/sys/windows/process.rs index be442f413740a..4974a8de89c79 100644 --- a/src/libstd/sys/windows/process.rs +++ b/src/libstd/sys/windows/process.rs @@ -487,9 +487,7 @@ fn make_command_line(prog: &OsStr, args: &[OsString]) -> io::Result> { } else { if x == '"' as u16 { // Add n+1 backslashes to total 2n+1 before internal '"'. - for _ in 0..(backslashes+1) { - cmd.push('\\' as u16); - } + cmd.extend((0..(backslashes + 1)).map(|_| '\\' as u16)); } backslashes = 0; } @@ -498,9 +496,7 @@ fn make_command_line(prog: &OsStr, args: &[OsString]) -> io::Result> { if quote { // Add n backslashes to total 2n before ending '"'. - for _ in 0..backslashes { - cmd.push('\\' as u16); - } + cmd.extend((0..backslashes).map(|_| '\\' as u16)); cmd.push('"' as u16); } Ok(()) diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs index 1b6b47f5489d7..d59c9dd6b53e8 100644 --- a/src/libsyntax/ast.rs +++ b/src/libsyntax/ast.rs @@ -500,10 +500,7 @@ impl Pat { PatKind::Slice(pats, None, _) if pats.len() == 1 => pats[0].to_ty().map(TyKind::Slice)?, PatKind::Tuple(pats, None) => { - let mut tys = Vec::new(); - for pat in pats { - tys.push(pat.to_ty()?); - } + let tys = pats.iter().map(|pat| pat.to_ty()).collect::>>()?; TyKind::Tup(tys) } _ => return None, @@ -949,10 +946,7 @@ impl Expr { ExprKind::Array(exprs) if exprs.len() == 1 => exprs[0].to_ty().map(TyKind::Slice)?, ExprKind::Tup(exprs) => { - let mut tys = Vec::new(); - for expr in exprs { - tys.push(expr.to_ty()?); - } + let tys = exprs.iter().map(|expr| expr.to_ty()).collect::>>()?; TyKind::Tup(tys) } ExprKind::Binary(binop, lhs, rhs) if binop.node == BinOpKind::Add => diff --git a/src/libsyntax/parse/lexer/mod.rs b/src/libsyntax/parse/lexer/mod.rs index 4b077aa8dd4c6..f9b9e95ead1b6 100644 --- a/src/libsyntax/parse/lexer/mod.rs +++ b/src/libsyntax/parse/lexer/mod.rs @@ -265,9 +265,7 @@ impl<'a> StringReader<'a> { m.push(c); } _ => { - for c in c.escape_default() { - m.push(c); - } + m.extend(c.escape_default()); } } } diff --git a/src/libsyntax_ext/deriving/decodable.rs b/src/libsyntax_ext/deriving/decodable.rs index 1e04d8fa22a67..c2b9294499907 100644 --- a/src/libsyntax_ext/deriving/decodable.rs +++ b/src/libsyntax_ext/deriving/decodable.rs @@ -131,8 +131,8 @@ fn decodable_substructure(cx: &mut ExtCtxt, StaticEnum(_, ref fields) => { let variant = cx.ident_of("i"); - let mut arms = Vec::new(); - let mut variants = Vec::new(); + let mut arms = Vec::with_capacity(fields.len() + 1); + let mut variants = Vec::with_capacity(fields.len()); let rvariant_arg = cx.ident_of("read_enum_variant_arg"); for (i, &(ident, v_span, ref parts)) in fields.iter().enumerate() { diff --git a/src/libsyntax_ext/deriving/generic/mod.rs b/src/libsyntax_ext/deriving/generic/mod.rs index a9f60fd053c07..e0f985c26c7a1 100644 --- a/src/libsyntax_ext/deriving/generic/mod.rs +++ b/src/libsyntax_ext/deriving/generic/mod.rs @@ -188,6 +188,7 @@ pub use self::StaticFields::*; pub use self::SubstructureFields::*; use std::cell::RefCell; +use std::iter; use std::vec; use rustc_target::spec::abi::Abi; @@ -558,15 +559,13 @@ impl<'a> TraitDef<'a> { // type being derived upon self.additional_bounds.iter().map(|p| { cx.trait_bound(p.to_path(cx, self.span, type_ident, generics)) - }).collect(); - - // require the current trait - bounds.push(cx.trait_bound(trait_path.clone())); - - // also add in any bounds from the declaration - for declared_bound in ¶m.bounds { - bounds.push((*declared_bound).clone()); - } + }).chain( + // require the current trait + iter::once(cx.trait_bound(trait_path.clone())) + ).chain( + // also add in any bounds from the declaration + param.bounds.iter().cloned() + ).collect(); cx.typaram(self.span, param.ident, vec![], bounds, None) } diff --git a/src/libsyntax_ext/deriving/hash.rs b/src/libsyntax_ext/deriving/hash.rs index 7d22998487ba7..950e8c84f1765 100644 --- a/src/libsyntax_ext/deriving/hash.rs +++ b/src/libsyntax_ext/deriving/hash.rs @@ -95,9 +95,8 @@ fn hash_substructure(cx: &mut ExtCtxt, trait_span: Span, substr: &Substructure) _ => cx.span_bug(trait_span, "impossible substructure in `derive(Hash)`"), }; - for &FieldInfo { ref self_, span, .. } in fields { - stmts.push(call_hash(span, self_.clone())); - } + stmts.extend(fields.iter().map(|FieldInfo { ref self_, span, .. }| + call_hash(*span, self_.clone()))); cx.expr_block(cx.block(trait_span, stmts)) } diff --git a/src/libsyntax_ext/format.rs b/src/libsyntax_ext/format.rs index 98de3d80b1e1f..46c85497ee78f 100644 --- a/src/libsyntax_ext/format.rs +++ b/src/libsyntax_ext/format.rs @@ -406,10 +406,7 @@ impl<'a, 'b> Context<'a, 'b> { // Map the arguments for i in 0..args_len { let ref arg_types = self.arg_types[i]; - let mut arg_offsets = Vec::with_capacity(arg_types.len()); - for offset in arg_types { - arg_offsets.push(sofar + *offset); - } + let arg_offsets = arg_types.iter().map(|offset| sofar + *offset).collect::>(); self.arg_index_map.push(arg_offsets); sofar += self.arg_unique_types[i].len(); } @@ -581,10 +578,12 @@ impl<'a, 'b> Context<'a, 'b> { /// Actually builds the expression which the format_args! block will be /// expanded to fn into_expr(self) -> P { - let mut locals = Vec::new(); - let mut counts = Vec::new(); - let mut pats = Vec::new(); - let mut heads = Vec::new(); + let mut locals = Vec::with_capacity( + (0..self.args.len()).map(|i| self.arg_unique_types[i].len()).sum() + ); + let mut counts = Vec::with_capacity(self.count_args.len()); + let mut pats = Vec::with_capacity(self.args.len()); + let mut heads = Vec::with_capacity(self.args.len()); let names_pos: Vec<_> = (0..self.args.len()) .map(|i| self.ecx.ident_of(&format!("arg{}", i)).gensym())