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use {Buf, BufMut, IntoBuf, Bytes, BytesMut}; /// Conversion from a [`Buf`] /// /// Implementing `FromBuf` for a type defines how it is created from a buffer. /// This is common for types which represent byte storage of some kind. /// /// [`FromBuf::from_buf`] is rarely called explicitly, and it is instead used /// through [`Buf::collect`]. See [`Buf::collect`] documentation for more examples. /// /// See also [`IntoBuf`]. /// /// # Examples /// /// Basic usage: /// /// ``` /// use bytes::{Bytes, IntoBuf}; /// use bytes::buf::FromBuf; /// /// let buf = Bytes::from(&b"hello world"[..]).into_buf(); /// let vec = Vec::from_buf(buf); /// /// assert_eq!(vec, &b"hello world"[..]); /// ``` /// /// Using [`Buf::collect`] to implicitly use `FromBuf`: /// /// ``` /// use bytes::{Buf, Bytes, IntoBuf}; /// /// let buf = Bytes::from(&b"hello world"[..]).into_buf(); /// let vec: Vec<u8> = buf.collect(); /// /// assert_eq!(vec, &b"hello world"[..]); /// ``` /// /// Implementing `FromBuf` for your type: /// /// ``` /// use bytes::{BufMut, Bytes}; /// use bytes::buf::{IntoBuf, FromBuf}; /// /// // A sample buffer, that's just a wrapper over Vec<u8> /// struct MyBuffer(Vec<u8>); /// /// impl FromBuf for MyBuffer { /// fn from_buf<B>(buf: B) -> Self where B: IntoBuf { /// let mut v = Vec::new(); /// v.put(buf.into_buf()); /// MyBuffer(v) /// } /// } /// /// // Now we can make a new buf /// let buf = Bytes::from(&b"hello world"[..]); /// /// // And make a MyBuffer out of it /// let my_buf = MyBuffer::from_buf(buf); /// /// assert_eq!(my_buf.0, &b"hello world"[..]); /// ``` /// /// [`Buf`]: trait.Buf.html /// [`FromBuf::from_buf`]: #method.from_buf /// [`Buf::collect`]: trait.Buf.html#method.collect /// [`IntoBuf`]: trait.IntoBuf.html pub trait FromBuf { /// Creates a value from a buffer. /// /// See the [type-level documentation](#) for more details. /// /// # Examples /// /// Basic usage: /// /// ``` /// use bytes::{Bytes, IntoBuf}; /// use bytes::buf::FromBuf; /// /// let buf = Bytes::from(&b"hello world"[..]).into_buf(); /// let vec = Vec::from_buf(buf); /// /// assert_eq!(vec, &b"hello world"[..]); /// ``` fn from_buf<T>(buf: T) -> Self where T: IntoBuf; } impl FromBuf for Vec<u8> { fn from_buf<T>(buf: T) -> Self where T: IntoBuf { let buf = buf.into_buf(); let mut ret = Vec::with_capacity(buf.remaining()); ret.put(buf); ret } } impl FromBuf for Bytes { fn from_buf<T>(buf: T) -> Self where T: IntoBuf { BytesMut::from_buf(buf).freeze() } } impl FromBuf for BytesMut { fn from_buf<T>(buf: T) -> Self where T: IntoBuf { let buf = buf.into_buf(); let mut ret = BytesMut::with_capacity(buf.remaining()); ret.put(buf); ret } }