cargo expand --test no_std (https://github.com/colin-kiegel/rust-derive-builder/pull/45)

no_std_expanded.rs

#![feature(prelude_import)]
#![no_std]
#![no_std]
#![feature(collections)]
#![allow(dead_code)]
#[prelude_import]
use core::prelude::v1::*;
#[macro_use]
extern crate core as core;

#[macro_use]
extern crate derive_builder;
extern crate collections;

struct IgnoreEmptyStruct {}
#[doc =
      // this is just a compile-test - no run time checks required.

      "Builder for `IgnoreEmptyStruct`.\n\n# Examples\n\n```rust\nlet builder = <IgnoreEmptyStructBuilder as Default>::default();\n// .. call some setters on `builder`\nlet _x: Result<IgnoreEmptyStruct, String> = builder.build();\n```\n"]
struct IgnoreEmptyStructBuilder {}
#[automatically_derived]
#[allow(unused_qualifications)]
impl ::core::default::Default for IgnoreEmptyStructBuilder {
    #[inline]
    fn default() -> IgnoreEmptyStructBuilder {
        IgnoreEmptyStructBuilder {}
    }
}
#[automatically_derived]
#[allow(unused_qualifications)]
impl ::core::clone::Clone for IgnoreEmptyStructBuilder {
    #[inline]
    fn clone(&self) -> IgnoreEmptyStructBuilder {
        match *self {
            IgnoreEmptyStructBuilder {} => IgnoreEmptyStructBuilder {},
        }
    }
}
#[allow(dead_code)]
impl IgnoreEmptyStructBuilder {
    #[doc =
          "Builds a new `IgnoreEmptyStruct`.\n\n# Errors\n\nIf some field has not been initialized.\n"]
    #[cfg(not(no_std))]
    fn build(&self) -> ::std::result::Result<IgnoreEmptyStruct, ::std::string::String> {
        Ok(IgnoreEmptyStruct {})
    }
}
#[test]
pub fn empty_struct() {}
#[test]
pub fn write_docs() {
    {
        static _MSG_FILE_LINE: (&'static str, &'static str, u32) =
            ("not yet implemented", "tests/no_std.rs", 19u32);
        ::panicking::panic(&_MSG_FILE_LINE)
    }
}
pub mod __test_reexports {
    #[allow(private_in_public)]
    pub use super::empty_struct;
    #[allow(private_in_public)]
    pub use super::write_docs;
}
pub mod __test {
    extern crate test;
    #[main]
    pub fn main() -> () {
        test::test_main_static(TESTS)
    }
    const TESTS: &'static [self::test::TestDescAndFn] =
        &[self::test::TestDescAndFn {
              desc: self::test::TestDesc {
                  name: self::test::StaticTestName("empty_struct"),
                  ignore: false,
                  should_panic: self::test::ShouldPanic::No,
              },
              testfn: self::test::StaticTestFn(::__test_reexports::empty_struct),
          },
          self::test::TestDescAndFn {
              desc: self::test::TestDesc {
                  name: self::test::StaticTestName("write_docs"),
                  ignore: false,
                  should_panic: self::test::ShouldPanic::No,
              },
              testfn: self::test::StaticTestFn(::__test_reexports::write_docs),
          }];
}