bitcoin_num 0.2.3

// Bitcoin Numeric Library
// Written in 2014 by
//     Andrew Poelstra <apoelstra@wpsoftware.net>
//
// To the extent possible under law, the author(s) have dedicated all
// copyright and related and neighboring rights to this software to
// the public domain worldwide. This software is distributed without
// any warranty.
//
// You should have received a copy of the CC0 Public Domain Dedication
// along with this software.
// If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.
//

//! Internal Macros
//!
//! Macros meant to be used inside the Rust Bitcoin library

/// Implements standard array methods for a given wrapper type
macro_rules! impl_array_newtype {
    ($thing:ident, $ty:ty, $len:expr) => {
        impl $thing {
            #[inline]
            /// Converts the object to a raw pointer
            pub fn as_ptr(&self) -> *const $ty {
                let &$thing(ref dat) = self;
                dat.as_ptr()
            }

            #[inline]
            /// Converts the object to a mutable raw pointer
            pub fn as_mut_ptr(&mut self) -> *mut $ty {
                let &mut $thing(ref mut dat) = self;
                dat.as_mut_ptr()
            }

            #[inline]
            /// Returns the length of the object as an array
            pub fn len(&self) -> usize {
                $len
            }

            #[inline]
            /// Returns whether the object, as an array, is empty. Always false.
            pub fn is_empty(&self) -> bool {
                false
            }

            #[inline]
            /// Returns the underlying bytes.
            pub fn as_bytes(&self) -> &[$ty; $len] {
                &self.0
            }

            #[inline]
            /// Returns the underlying bytes.
            pub fn to_bytes(&self) -> [$ty; $len] {
                self.0.clone()
            }

            #[inline]
            /// Returns the underlying bytes.
            pub fn into_bytes(self) -> [$ty; $len] {
                self.0
            }
        }

        impl<'a> ::core::convert::From<&'a [$ty]> for $thing {
            fn from(data: &'a [$ty]) -> $thing {
                assert_eq!(data.len(), $len);
                let mut ret = [0; $len];
                ret.copy_from_slice(&data[..]);
                $thing(ret)
            }
        }

        impl ::core::ops::Index<usize> for $thing {
            type Output = $ty;

            #[inline]
            fn index(&self, index: usize) -> &$ty {
                let &$thing(ref dat) = self;
                &dat[index]
            }
        }

        impl_index_newtype!($thing, $ty);

        impl ::core::cmp::PartialEq for $thing {
            #[inline]
            fn eq(&self, other: &$thing) -> bool {
                &self[..] == &other[..]
            }
        }

        impl ::core::cmp::Eq for $thing {}

        impl ::core::cmp::PartialOrd for $thing {
            #[inline]
            fn partial_cmp(&self, other: &$thing) -> Option<::core::cmp::Ordering> {
                Some(self.cmp(&other))
            }
        }

        impl ::core::cmp::Ord for $thing {
            #[inline]
            fn cmp(&self, other: &$thing) -> ::core::cmp::Ordering {
                // manually implement comparison to get little-endian ordering
                // (we need this for our numeric types; non-numeric ones shouldn't
                // be ordered anyway except to put them in BTrees or whatever, and
                // they don't care how we order as long as we're consistent).
                for i in 0..$len {
                    if self[$len - 1 - i] < other[$len - 1 - i] {
                        return ::core::cmp::Ordering::Less;
                    }
                    if self[$len - 1 - i] > other[$len - 1 - i] {
                        return ::core::cmp::Ordering::Greater;
                    }
                }
                ::core::cmp::Ordering::Equal
            }
        }

        #[cfg_attr(feature = "clippy", allow(expl_impl_clone_on_copy))] // we don't define the `struct`, we have to explicitly impl
        impl ::core::clone::Clone for $thing {
            #[inline]
            fn clone(&self) -> $thing {
                $thing::from(&self[..])
            }
        }

        impl ::core::marker::Copy for $thing {}

        impl ::core::hash::Hash for $thing {
            #[inline]
            fn hash<H>(&self, state: &mut H)
            where
                H: ::core::hash::Hasher,
            {
                (&self[..]).hash(state);
            }

            fn hash_slice<H>(data: &[$thing], state: &mut H)
            where
                H: ::core::hash::Hasher,
            {
                for d in data.iter() {
                    (&d[..]).hash(state);
                }
            }
        }
    };
}

/// Implements standard indexing methods for a given wrapper type
macro_rules! impl_index_newtype {
    ($thing:ident, $ty:ty) => {
        impl ::core::ops::Index<::core::ops::Range<usize>> for $thing {
            type Output = [$ty];

            #[inline]
            fn index(&self, index: ::core::ops::Range<usize>) -> &[$ty] {
                &self.0[index]
            }
        }

        impl ::core::ops::Index<::core::ops::RangeTo<usize>> for $thing {
            type Output = [$ty];

            #[inline]
            fn index(&self, index: ::core::ops::RangeTo<usize>) -> &[$ty] {
                &self.0[index]
            }
        }

        impl ::core::ops::Index<::core::ops::RangeFrom<usize>> for $thing {
            type Output = [$ty];

            #[inline]
            fn index(&self, index: ::core::ops::RangeFrom<usize>) -> &[$ty] {
                &self.0[index]
            }
        }

        impl ::core::ops::Index<::core::ops::RangeFull> for $thing {
            type Output = [$ty];

            #[inline]
            fn index(&self, _: ::core::ops::RangeFull) -> &[$ty] {
                &self.0[..]
            }
        }
    };
}

/// Implements several traits for byte-based newtypes.
/// Implements:
/// - std::fmt::LowerHex (implies hashes::hex::ToHex)
/// - std::fmt::Display
/// - std::str::FromStr
/// - hashes::hex::FromHex
#[macro_export]
macro_rules! impl_bytes_newtype {
    ($t:ident, $len:expr) => (

        impl ::core::fmt::LowerHex for $t {
            fn fmt(&self, f: &mut ::core::fmt::Formatter) -> ::core::fmt::Result {
                for &ch in self.0.iter() {
                    write!(f, "{:02x}", ch)?;
                }
                Ok(())
            }
        }

        impl ::core::fmt::Display for $t {
            fn fmt(&self, f: &mut ::core::fmt::Formatter) -> ::core::fmt::Result {
                fmt::LowerHex::fmt(self, f)
            }
        }

        impl $crate::hex::FromHex for $t {
            fn from_byte_iter<I>(iter: I) -> Result<Self, $crate::hex::Error>
                where I: ::core::iter::Iterator<Item=Result<u8, $crate::hex::Error>> +
                    ::core::iter::ExactSizeIterator +
                    ::core::iter::DoubleEndedIterator,
            {
                if iter.len() == $len {
                    let mut ret = [0; $len];
                    for (n, byte) in iter.enumerate() {
                        ret[n] = byte?;
                    }
                    Ok($t(ret))
                } else {
                    Err($crate::hex::Error::InvalidLength(2 * $len, 2 * iter.len()))
                }
            }
        }

        impl ::core::str::FromStr for $t {
            type Err = $crate:::hex::Error;
            fn from_str(s: &str) -> Result<Self, Self::Err> {
                $crate::hex::FromHex::from_hex(s)
            }
        }

        #[cfg(feature="serde")]
        impl $crate::serde::Serialize for $t {
            fn serialize<S: $crate::serde::Serializer>(&self, s: S) -> Result<S::Ok, S::Error> {
                if s.is_human_readable() {
                    s.serialize_str(&$crate::hex::ToHex::to_hex(self))
                } else {
                    s.serialize_bytes(&self[..])
                }
            }
        }

        #[cfg(feature="serde")]
        impl<'de> $crate::serde::Deserialize<'de> for $t {
            fn deserialize<D: $crate::serde::Deserializer<'de>>(d: D) -> Result<$t, D::Error> {
                if d.is_human_readable() {
                    struct HexVisitor;

                    impl<'de> $crate::serde::de::Visitor<'de> for HexVisitor {
                        type Value = $t;

                        fn expecting(&self, formatter: &mut ::core::fmt::Formatter) -> ::core::fmt::Result {
                            formatter.write_str("an ASCII hex string")
                        }

                        fn visit_bytes<E>(self, v: &[u8]) -> Result<Self::Value, E>
                        where
                            E: $crate::serde::de::Error,
                        {
                            if let Ok(hex) = ::core::str::from_utf8(v) {
                                $crate::hex::FromHex::from_hex(hex).map_err(E::custom)
                            } else {
                                return Err(E::invalid_value($crate::serde::de::Unexpected::Bytes(v), &self));
                            }
                        }

                        fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
                        where
                            E: $crate::serde::de::Error,
                        {
                            $crate::hex::FromHex::from_hex(v).map_err(E::custom)
                        }
                    }

                    d.deserialize_str(HexVisitor)
                } else {
                    struct BytesVisitor;

                    impl<'de> $crate::serde::de::Visitor<'de> for BytesVisitor {
                        type Value = $t;

                        fn expecting(&self, formatter: &mut ::core::fmt::Formatter) -> ::core::fmt::Result {
                            formatter.write_str("a bytestring")
                        }

                        fn visit_bytes<E>(self, v: &[u8]) -> Result<Self::Value, E>
                        where
                            E: $crate::serde::de::Error,
                        {
                            if v.len() != $len {
                                Err(E::invalid_length(v.len(), &stringify!($len)))
                            } else {
                                let mut ret = [0; $len];
                                ret.copy_from_slice(v);
                                Ok($t(ret))
                            }
                        }
                    }

                    d.deserialize_bytes(BytesVisitor)
                }
            }
        }
    )
}