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Merged
merged 1 commit into from
Mar 29, 2015
Merged

Remove IteratorExt #23300

merged 1 commit into from
Mar 29, 2015

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sfackler
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All methods are inlined into Iterator with Self: Sized bounds to make
sure Iterator is still object safe.

[breaking-change]

This is blocked on ICEs: https://gist.github.com/sfackler/5aff7c57cf8d896e2c6f
Seem to be similar to #23281.

@rust-highfive
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r? @alexcrichton

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alexcrichton
alexcrichton reviewed Mar 12, 2015
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src/libcore/iter.rs
@@ -200,7 +147,7 @@ pub trait IteratorExt: Iterator + Sized {
/// ```
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
fn nth(&mut self, mut n: usize) -> Option<Self::Item> {
fn nth(&mut self, mut n: usize) -> Option<Self::Item> where Self: Sized {
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I think that functions like this which can relax the Self: Sized bound are ok to. In theory an iterator could override this method to provide a specialized implementation.

@alexcrichton
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I'm ok merging this as-is basically (nit or not), so r=me once the ICE is fixed

@bors
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bors commented Mar 16, 2015

☔ The latest upstream changes (presumably #23342) made this pull request unmergeable. Please resolve the merge conflicts.

@nikomatsakis
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@sfackler I'm investigating ICE now...

@nikomatsakis
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OK, I... sort of understand the ICE. The problem is constructing the vtable for an Iterator object when the type in question may not satisfy the where clauses. I'll have to poke at this tomorrow, there may be multiple bugs here, not sure at this moment of the best fix, but seems eminently solvable. :)

@nikomatsakis nikomatsakis mentioned this pull request Mar 17, 2015
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@nikomatsakis
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see #23435 for a smaller example and explanation of the ICE

@nikomatsakis
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#23438 should fix the ICE

@sfackler
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Awesome, thanks Niko!

@sfackler
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Rebased over @nikomatsakis's fix, but it looks like we're still running into a very similar crash: https://gist.github.com/sfackler/6bf9e4140c1890553528

@sfackler
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Backtrace:

stack backtrace:
   1:     0x7f4dcc8166e4 - sys::backtrace::write::hb2ecc26860cf26a5N0C
   2:     0x7f4dcc83df90 - panicking::on_panic::h960f9523a4558f10fhJ
   3:     0x7f4dcc772f4a - rt::unwind::begin_unwind_inner::h6b71715c6cd07544OXI
   4:     0x7f4dc9c357bd - rt::unwind::begin_unwind::h10330668448694945308
   5:     0x7f4dc9c35763 - diagnostic::SpanHandler::span_bug::ha94d4327955c6b76FaB
   6:     0x7f4dca4c1053 - session::Session::span_bug::ha063ab5cf89afb7arTn
   7:     0x7f4dcbfa18d5 - trans::monomorphize::normalize_associated_type::h15578180277037779921
   8:     0x7f4dcbf9cec5 - trans::meth::emit_vtable_methods::closure.46262
   9:     0x7f4dcbf9c230 - vec::Vec<T>.FromIterator<T>::from_iter::h14757000865658806530
  10:     0x7f4dcbf9a8c1 - trans::meth::emit_vtable_methods::h869b133958115c379By
  11:     0x7f4dcbf9ba5a - iter::FlatMap<I, U, F>.Iterator::next::closure.46232
  12:     0x7f4dcbf9b6e8 - iter::FlatMap<I, U, F>.Iterator::next::h18664991822273943
  13:     0x7f4dcbf9afcc - vec::Vec<T>.FromIterator<T>::from_iter::h1954666775356190594
  14:     0x7f4dcbedc3eb - trans::meth::get_vtable::hcdbf30f6716b5c22Svy
  15:     0x7f4dcbed7f12 - trans::expr::unsized_info::h1026628279121771536
  16:     0x7f4dcbee34c3 - trans::expr::apply_adjustments::apply_autoref::hfb6d70e6aeef5555Txh
  17:     0x7f4dcbe9076d - trans::expr::trans::hbd4f36981c222183ifh
  18:     0x7f4dcbe8e3e4 - trans::expr::trans_into::h2fbdf169c8afb1f608g
  19:     0x7f4dcbed769c - trans::expr::trans_rvalue_stmt_unadjusted::h0b4eefee561d46b3wgi
  20:     0x7f4dcbe8e9bd - trans::expr::trans_into::h2fbdf169c8afb1f608g
  21:     0x7f4dcbe8da34 - trans::controlflow::trans_stmt_semi::hf010868e8995b5e144d
  22:     0x7f4dcbe8f510 - trans::controlflow::trans_block::h1a3e1fe31adb4417R5d
  23:     0x7f4dcbf5739b - trans::base::trans_closure::h3785eaa409045c3cv7s
  24:     0x7f4dcbe793f8 - trans::base::trans_fn::hb17787e2baa85f80oit
  25:     0x7f4dcbe74f31 - trans::base::trans_item::h9d97a4e78d8fd135gGt
  26:     0x7f4dcbf5efcc - trans::base::trans_crate::h317d2891eb44f3c8KCu
  27:     0x7f4dccea22a3 - driver::phase_4_translate_to_llvm::hf105818bf70a091fmOa
  28:     0x7f4dcce7cee9 - driver::compile_input::ha7a5cd31f19269c3Rba
  29:     0x7f4dccf357b2 - run_compiler::hffd60a8ae6171fbbz2b
  30:     0x7f4dccf335ec - thunk::F.Invoke<A, R>::invoke::h17211452014221736608
  31:     0x7f4dccf327a9 - rt::unwind::try::try_fn::h10298546463733922815
  32:     0x7f4dcc8bc118 - rust_try_inner
  33:     0x7f4dcc8bc105 - rust_try
  34:     0x7f4dccf32b29 - thunk::F.Invoke<A, R>::invoke::h16798335321014197657
  35:     0x7f4dcc82b0d8 - sys::thread::create::thread_start::h870bf041dfc81c1bDQH
  36:     0x7f4dc67ba373 - start_thread
  37:     0x7f4dcc3e927c - __clone
  38:                0x0 - <unknown>

@nikomatsakis
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@sfackler hmm! I'll check it out again...

@nikomatsakis
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@sfackler ok I have a fix for the ICE now, but I don't have a good standalone test case yet. The problem seems to arise because I was previously trying to normalize first, when normalization itself can encounter errors.

@nikomatsakis nikomatsakis mentioned this pull request Mar 18, 2015
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@bors
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bors commented Mar 19, 2015

☔ The latest upstream changes (presumably #23482) made this pull request unmergeable. Please resolve the merge conflicts.

@sfackler
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This works rebased on top of #23486 so it should be good to go once that merges.

apasel422
apasel422 reviewed Mar 22, 2015
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src/libcore/iter.rs
@@ -928,7 +885,7 @@ pub trait IteratorExt: Iterator + Sized {
/// `std::usize::MAX` elements of the original iterator.
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
fn rev(self) -> Rev<Self> {
fn rev(self) -> Rev<Self> where Self: Sized {
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Can you make this where Self: Sized + DoubleEndedIterator in order to fix #23587?

@sfackler sfackler changed the title [WIP] Remove IteratorExt Remove IteratorExt Mar 28, 2015
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@bors r=alexcrichton 11f5ac6

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bors commented Mar 28, 2015

⌛ Testing commit 11f5ac6 with merge 2f4bad9...

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bors commented Mar 28, 2015

💔 Test failed - auto-win-64-nopt-t

@sfackler
Remove IteratorExt
d502f42 
All methods are inlined into Iterator with `Self: Sized` bounds to make
sure Iterator is still object safe.

[breaking-change]
@sfackler
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@bors: r=alexcrichton d502f42

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bors commented Mar 28, 2015

⌛ Testing commit d502f42 with merge c89de2c...

bors added a commit that referenced this pull request Mar 28, 2015
@bors
Auto merge of #23300 - sfackler:rm-iterator-ext, r=alexcrichton
c89de2c 
All methods are inlined into Iterator with `Self: Sized` bounds to make
sure Iterator is still object safe.

[breaking-change]

This is blocked on ICEs: https://gist.github.com/sfackler/5aff7c57cf8d896e2c6f
Seem to be similar to #23281.
@bors
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bors commented Mar 29, 2015

☀️ Test successful - auto-linux-32-nopt-t, auto-linux-32-opt, auto-linux-64-nopt-t, auto-linux-64-opt, auto-linux-64-x-android-t, auto-mac-32-opt, auto-mac-64-nopt-t, auto-mac-64-opt, auto-win-32-nopt-t, auto-win-32-opt, auto-win-64-nopt-t, auto-win-64-opt

@bors bors merged commit d502f42 into rust-lang:master Mar 29, 2015
@bors bors mentioned this pull request Mar 29, 2015
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@sfackler sfackler deleted the rm-iterator-ext branch November 26, 2016 05:50
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6 participants
@sfackler @rust-highfive @alexcrichton @bors @nikomatsakis @apasel422