Building for no_std environment (--no-default-features) fails on nightly.

[jasondavies]

Apologies if I'm missing something, but when attempting to build for no_std, I get the following errors:

% cargo build --no-default-features
   Compiling nom v3.2.0 (file:///Users/jason/src/nom)
error[E0432]: unresolved import `collections::boxed`
   --> src/lib.rs:423:25
    |
423 |   pub use collections::{boxed, vec, string};
    |                         ^^^^^ no `boxed` in the root

error[E0412]: cannot find type `Box` in this scope
  --> src/nom.rs:23:39
   |
23 | pub fn tag_cl<'a,'b>(rec:&'a[u8]) ->  Box<Fn(&'b[u8]) -> IResult<&'b[u8], &'b[u8]> + 'a> {
   |                                       ^^^ not found in this scope

error[E0433]: failed to resolve. Use of undeclared type or module `Box`
  --> src/nom.rs:24:3
   |
24 |   Box::new(move |i: &'b[u8]| -> IResult<&'b[u8], &'b[u8]> {
   |   ^^^ Use of undeclared type or module `Box`

error: aborting due to 3 previous errors

error: Could not compile `nom`.

To learn more, run the command again with --verbose.

Related #473.

% rustc --version
rustc 1.21.0-nightly (dd53dd5f9 2017-08-01)

[jasondavies]

Oh, just discovered #537, which seems to resolve the errors.

[Geal]

Hi, the PR has been merged in the "result" branch and will be available for nom 4.0

[Geal]

there's been follow-up work on that, and now since 9b12a2d there's an internal module (lib) that imports stuff from alloc and std if specified.
The interesting part being that the parts requiring std are very reduced now, and you can specify alloc to get many0 and many1