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

#![doc = include_str!("../README.md")]
#![doc(test(
    no_crate_inject,
    attr(
        deny(warnings, rust_2018_idioms, single_use_lifetimes),
        allow(dead_code, unused_variables)
    )
))]
#![forbid(unsafe_code)]
#![warn(rust_2018_idioms, single_use_lifetimes, unreachable_pub)]
#![warn(clippy::pedantic)]

// older compilers require explicit `extern crate`.
#[allow(unused_extern_crates)]
extern crate proc_macro;

use derive_utils::{derive_trait, quick_derive};
use proc_macro::TokenStream;
use syn::{parse_macro_input, parse_quote};

#[proc_macro_derive(Read)]
pub fn derive_read(input: TokenStream) -> TokenStream {
    // TODO: When `read_buf` stabilized, add `read_buf` conditionally.

    derive_trait(&parse_macro_input!(input), parse_quote!(::std::io::Read), None, parse_quote! {
        trait Read {
            #[inline]
            fn read(&mut self, buf: &mut [u8]) -> ::std::io::Result<usize>;
            #[inline]
            fn read_to_end(&mut self, buf: &mut ::std::vec::Vec<u8>) -> ::std::io::Result<usize>;
            #[inline]
            fn read_to_string(
                &mut self,
                buf: &mut ::std::string::String,
            ) -> ::std::io::Result<usize>;
            #[inline]
            fn read_exact(&mut self, buf: &mut [u8]) -> ::std::io::Result<()>;
            #[inline]
            fn read_vectored(
                &mut self, bufs: &mut [::std::io::IoSliceMut<'_>],
            ) -> ::std::io::Result<usize>;
        }
    })
    .into()
}

#[proc_macro_derive(BufRead)]
pub fn derive_buf_read(input: TokenStream) -> TokenStream {
    quick_derive! {
        input,
        ::std::io::BufRead,
        trait BufRead {
            #[inline]
            fn fill_buf(&mut self) -> ::std::io::Result<&[u8]>;
            #[inline]
            fn consume(&mut self, amt: usize);
            #[inline]
            fn read_until(
                &mut self, byte: u8, buf: &mut ::std::vec::Vec<u8>,
            ) -> ::std::io::Result<usize>;
            #[inline]
            fn read_line(&mut self, buf: &mut ::std::string::String) -> ::std::io::Result<usize>;
        }
    }
}

#[proc_macro_derive(Write)]
pub fn derive_write(input: TokenStream) -> TokenStream {
    derive_trait(&parse_macro_input!(input), parse_quote!(::std::io::Write), None, parse_quote! {
        trait Write {
            #[inline]
            fn write(&mut self, buf: &[u8]) -> ::std::io::Result<usize>;
            #[inline]
            fn flush(&mut self) -> ::std::io::Result<()>;
            #[inline]
            fn write_all(&mut self, buf: &[u8]) -> ::std::io::Result<()>;
            #[inline]
            fn write_fmt(&mut self, fmt: ::std::fmt::Arguments<'_>) -> ::std::io::Result<()>;
            #[inline]
            fn write_vectored(
                &mut self,
                bufs: &[::std::io::IoSlice<'_>],
            ) -> ::std::io::Result<usize>;
        }
    })
    .into()
}

#[proc_macro_derive(Seek)]
pub fn derive_seek(input: TokenStream) -> TokenStream {
    quick_derive! {
        input,
        ::std::io::Seek,
        trait Seek {
            #[inline]
            fn seek(&mut self, pos: ::std::io::SeekFrom) -> ::std::io::Result<u64>;
        }
    }
}