      1
      2
      3
      4
      5
      6
      7
      8
      9
     10
     11
     12
     13
     14
     15
     16
     17
     18
     19
     20
     21
     22
     23
     24
     25
     26
     27
     28
     29
     30
     31
     32
     33
     34
     35
     36
     37
     38
     39
     40
     41
     42
     43
     44
     45
     46
     47
     48
     49
     50
     51
     52
     53
     54
     55
     56
     57
     58
     59
     60
     61
     62
     63
     64
     65
     66
     67
     68
     69
     70
     71
     72
     73
     74
     75
     76
     77
     78
     79
     80
     81
     82
     83
     84
     85
     86
     87
     88
     89
     90
     91
     92
     93
     94
     95
     96
     97
     98
     99
    100
    101
    102
    103
    104
    105
    106
    107
    108

    /// A macro for defining #[cfg] if-else statements.
    ///
    /// This is similar to the `if/elif` C preprocessor macro by allowing definition
    /// of a cascade of `#[cfg]` cases, emitting the implementation which matches
    /// first.
    ///
    /// This allows you to conveniently provide a long list #[cfg]'d blocks of code
    /// without having to rewrite each clause multiple times.
    macro_rules! cfg_if {
        ($(
            if #[cfg($($meta:meta),*)] { $($it:item)* }
        ) else * else {
            $($it2:item)*
        }) => {
            __cfg_if_items! {
                () ;
                $( ( ($($meta),*) ($($it)*) ), )*
                ( () ($($it2)*) ),
            }
        }
    }

    macro_rules! __cfg_if_items {
        (($($not:meta,)*) ; ) => {};
        (($($not:meta,)*) ; ( ($($m:meta),*) ($($it:item)*) ), $($rest:tt)*) => {
            __cfg_if_apply! { cfg(all(not(any($($not),*)), $($m,)*)), $($it)* }
            __cfg_if_items! { ($($not,)* $($m,)*) ; $($rest)* }
        }
    }

    macro_rules! __cfg_if_apply {
        ($m:meta, $($it:item)*) => {
            $(#[$m] $it)*
        }
    }

    macro_rules! s {
        ($($(#[$attr:meta])* pub struct $i:ident { $($field:tt)* })*) => ($(
            __item! {
                #[repr(C)]
                $(#[$attr])*
                pub struct $i { $($field)* }
            }
            impl ::dox::Copy for $i {}
            impl ::dox::Clone for $i {
                fn clone(&self) -> $i { *self }
            }
        )*)
    }

    macro_rules! f {
        ($(pub fn $i:ident($($arg:ident: $argty:ty),*) -> $ret:ty {
            $($body:stmt);*
        })*) => ($(
            #[inline]
            #[cfg(not(dox))]
            pub unsafe extern fn $i($($arg: $argty),*) -> $ret {
                $($body);*
            }

            #[cfg(dox)]
            #[allow(dead_code)]
            pub unsafe extern fn $i($($arg: $argty),*) -> $ret {
                loop {}
            }
        )*)
    }

    macro_rules! __item {
        ($i:item) => ($i)
    }

    #[cfg(test)]
    mod tests {
        cfg_if! {
            if #[cfg(test)] {
                use std::option::Option as Option2;
                fn works1() -> Option2<u32> { Some(1) }
            } else {
                fn works1() -> Option<u32> { None }
            }
        }

        cfg_if! {
            if #[cfg(foo)] {
                fn works2() -> bool { false }
            } else if #[cfg(test)] {
                fn works2() -> bool { true }
            } else {
                fn works2() -> bool { false }
            }
        }

        cfg_if! {
            if #[cfg(foo)] {
                fn works3() -> bool { false }
            } else {
                fn works3() -> bool { true }
            }
        }

        #[test]
        fn it_works() {
            assert!(works1().is_some());
            assert!(works2());
            assert!(works3());
        }
    }

# Help

## Keyboard Shortcuts

?
  Show this help dialog
S
  Focus the search field
⇤
  Move up in search results
⇥
  Move down in search results
⏎
  Go to active search result
+
  Collapse/expand all sections

## Search Tricks

Prefix searches with a type followed by a colon (e.g. `fn:`) to restrict the search to a given type.

Accepted types are: `fn`, `mod`, `struct`, `enum`, `trait`, `type`, `macro`, and `const`.

Search functions by type signature (e.g. `vec -> usize` or `* -> vec`)