# Trait byteorder::ReadBytesExt [−] [src]

    pub trait ReadBytesExt: Read {
        fn read_u8(&mut self) -> Result<u8> { ... }
        fn read_i8(&mut self) -> Result<i8> { ... }
        fn read_u16<T: ByteOrder>(&mut self) -> Result<u16> { ... }
        fn read_i16<T: ByteOrder>(&mut self) -> Result<i16> { ... }
        fn read_u24<T: ByteOrder>(&mut self) -> Result<u32> { ... }
        fn read_i24<T: ByteOrder>(&mut self) -> Result<i32> { ... }
        fn read_u32<T: ByteOrder>(&mut self) -> Result<u32> { ... }
        fn read_i32<T: ByteOrder>(&mut self) -> Result<i32> { ... }
        fn read_u64<T: ByteOrder>(&mut self) -> Result<u64> { ... }
        fn read_i64<T: ByteOrder>(&mut self) -> Result<i64> { ... }
        fn read_uint<T: ByteOrder>(&mut self, nbytes: usize) -> Result<u64> { ... }
        fn read_int<T: ByteOrder>(&mut self, nbytes: usize) -> Result<i64> { ... }
        fn read_f32<T: ByteOrder>(&mut self) -> Result<f32> { ... }
        fn read_f64<T: ByteOrder>(&mut self) -> Result<f64> { ... }
        fn read_u16_into<T: ByteOrder>(&mut self, dst: &mut [u16]) -> Result<()> { ... }
        fn read_u32_into<T: ByteOrder>(&mut self, dst: &mut [u32]) -> Result<()> { ... }
        fn read_u64_into<T: ByteOrder>(&mut self, dst: &mut [u64]) -> Result<()> { ... }
        fn read_i16_into<T: ByteOrder>(&mut self, dst: &mut [i16]) -> Result<()> { ... }
        fn read_i32_into<T: ByteOrder>(&mut self, dst: &mut [i32]) -> Result<()> { ... }
        fn read_i64_into<T: ByteOrder>(&mut self, dst: &mut [i64]) -> Result<()> { ... }
        unsafe fn read_f32_into_unchecked<T: ByteOrder>(
            &mut self,
            dst: &mut [f32]
        ) -> Result<()> { ... }
        unsafe fn read_f64_into_unchecked<T: ByteOrder>(
            &mut self,
            dst: &mut [f64]
        ) -> Result<()> { ... }
    }

Extends `Read` with methods for reading numbers. (For `std::io`.)

Most of the methods defined here have an unconstrained type parameter that must be explicitly instantiated. Typically, it is instantiated with either the `BigEndian` or `LittleEndian` types defined in this crate.

# Examples

Read unsigned 16 bit big-endian integers from a `Read`:

    use std::io::Cursor;
    use byteorder::{BigEndian, ReadBytesExt};

    let mut rdr = Cursor::new(vec![2, 5, 3, 0]);
    assert_eq!(517, rdr.read_u16::<BigEndian>().unwrap());
    assert_eq!(768, rdr.read_u16::<BigEndian>().unwrap());

## Provided Methods

### `fn read_u8(&mut self) -> Result<u8>`

Reads an unsigned 8 bit integer from the underlying reader.

Note that since this reads a single byte, no byte order conversions are used. It is included for completeness.

# Errors

This method returns the same errors as `Read::read_exact`.

# Examples

Read unsigned 8 bit integers from a `Read`:

    use std::io::Cursor;
    use byteorder::{BigEndian, ReadBytesExt};

    let mut rdr = Cursor::new(vec![2, 5]);
    assert_eq!(2, rdr.read_u8().unwrap());
    assert_eq!(5, rdr.read_u8().unwrap());

### `fn read_i8(&mut self) -> Result<i8>`

Reads a signed 8 bit integer from the underlying reader.

Note that since this reads a single byte, no byte order conversions are used. It is included for completeness.

# Errors

This method returns the same errors as `Read::read_exact`.

# Examples

Read unsigned 8 bit integers from a `Read`:

    use std::io::Cursor;
    use byteorder::{BigEndian, ReadBytesExt};

    let mut rdr = Cursor::new(vec![0x02, 0xfb]);
    assert_eq!(2, rdr.read_i8().unwrap());
    assert_eq!(-5, rdr.read_i8().unwrap());

### `fn read_u16<T: ByteOrder>(&mut self) -> Result<u16>`

Reads an unsigned 16 bit integer from the underlying reader.

# Errors

This method returns the same errors as `Read::read_exact`.

# Examples

Read unsigned 16 bit big-endian integers from a `Read`:

    use std::io::Cursor;
    use byteorder::{BigEndian, ReadBytesExt};

    let mut rdr = Cursor::new(vec![2, 5, 3, 0]);
    assert_eq!(517, rdr.read_u16::<BigEndian>().unwrap());
    assert_eq!(768, rdr.read_u16::<BigEndian>().unwrap());

### `fn read_i16<T: ByteOrder>(&mut self) -> Result<i16>`

Reads a signed 16 bit integer from the underlying reader.

# Errors

This method returns the same errors as `Read::read_exact`.

# Examples

Read signed 16 bit big-endian integers from a `Read`:

    use std::io::Cursor;
    use byteorder::{BigEndian, ReadBytesExt};

    let mut rdr = Cursor::new(vec![0x00, 0xc1, 0xff, 0x7c]);
    assert_eq!(193, rdr.read_i16::<BigEndian>().unwrap());
    assert_eq!(-132, rdr.read_i16::<BigEndian>().unwrap());

### `fn read_u24<T: ByteOrder>(&mut self) -> Result<u32>`

Reads an unsigned 24 bit integer from the underlying reader.

# Errors

This method returns the same errors as `Read::read_exact`.

# Examples

Read unsigned 24 bit big-endian integers from a `Read`:

    use std::io::Cursor;
    use byteorder::{BigEndian, ReadBytesExt};

    let mut rdr = Cursor::new(vec![0x00, 0x01, 0x0b]);
    assert_eq!(267, rdr.read_u24::<BigEndian>().unwrap());

### `fn read_i24<T: ByteOrder>(&mut self) -> Result<i32>`

Reads a signed 24 bit integer from the underlying reader.

# Errors

This method returns the same errors as `Read::read_exact`.

# Examples

Read signed 24 bit big-endian integers from a `Read`:

    use std::io::Cursor;
    use byteorder::{BigEndian, ReadBytesExt};

    let mut rdr = Cursor::new(vec![0xff, 0x7a, 0x33]);
    assert_eq!(-34253, rdr.read_i24::<BigEndian>().unwrap());

### `fn read_u32<T: ByteOrder>(&mut self) -> Result<u32>`

Reads an unsigned 32 bit integer from the underlying reader.

# Errors

This method returns the same errors as `Read::read_exact`.

# Examples

Read unsigned 32 bit big-endian integers from a `Read`:

    use std::io::Cursor;
    use byteorder::{BigEndian, ReadBytesExt};

    let mut rdr = Cursor::new(vec![0x00, 0x00, 0x01, 0x0b]);
    assert_eq!(267, rdr.read_u32::<BigEndian>().unwrap());

### `fn read_i32<T: ByteOrder>(&mut self) -> Result<i32>`

Reads a signed 32 bit integer from the underlying reader.

# Errors

This method returns the same errors as `Read::read_exact`.

# Examples

Read signed 32 bit big-endian integers from a `Read`:

    use std::io::Cursor;
    use byteorder::{BigEndian, ReadBytesExt};

    let mut rdr = Cursor::new(vec![0xff, 0xff, 0x7a, 0x33]);
    assert_eq!(-34253, rdr.read_i32::<BigEndian>().unwrap());

### `fn read_u64<T: ByteOrder>(&mut self) -> Result<u64>`

Reads an unsigned 64 bit integer from the underlying reader.

# Errors

This method returns the same errors as `Read::read_exact`.

# Examples

Read an unsigned 64 bit big-endian integer from a `Read`:

    use std::io::Cursor;
    use byteorder::{BigEndian, ReadBytesExt};

    let mut rdr = Cursor::new(vec![0x00, 0x03, 0x43, 0x95, 0x4d, 0x60, 0x86, 0x83]);
    assert_eq!(918733457491587, rdr.read_u64::<BigEndian>().unwrap());

### `fn read_i64<T: ByteOrder>(&mut self) -> Result<i64>`

Reads a signed 64 bit integer from the underlying reader.

# Errors

This method returns the same errors as `Read::read_exact`.

# Examples

Read a signed 64 bit big-endian integer from a `Read`:

    use std::io::Cursor;
    use byteorder::{BigEndian, ReadBytesExt};

    let mut rdr = Cursor::new(vec![0x80, 0, 0, 0, 0, 0, 0, 0]);
    assert_eq!(i64::min_value(), rdr.read_i64::<BigEndian>().unwrap());

### `fn read_uint<T: ByteOrder>(&mut self, nbytes: usize) -> Result<u64>`

Reads an unsigned n-bytes integer from the underlying reader.

# Errors

This method returns the same errors as `Read::read_exact`.

# Examples

Read an unsigned n-byte big-endian integer from a `Read`:

    use std::io::Cursor;
    use byteorder::{BigEndian, ReadBytesExt};

    let mut rdr = Cursor::new(vec![0x80, 0x74, 0xfa]);
    assert_eq!(8418554, rdr.read_uint::<BigEndian>(3).unwrap());

### `fn read_int<T: ByteOrder>(&mut self, nbytes: usize) -> Result<i64>`

Reads a signed n-bytes integer from the underlying reader.

# Errors

This method returns the same errors as `Read::read_exact`.

# Examples

Read an unsigned n-byte big-endian integer from a `Read`:

    use std::io::Cursor;
    use byteorder::{BigEndian, ReadBytesExt};

    let mut rdr = Cursor::new(vec![0xc1, 0xff, 0x7c]);
    assert_eq!(-4063364, rdr.read_int::<BigEndian>(3).unwrap());

### `fn read_f32<T: ByteOrder>(&mut self) -> Result<f32>`

Reads a IEEE754 single-precision (4 bytes) floating point number from the underlying reader.

# Errors

This method returns the same errors as `Read::read_exact`.

# Examples

Read a big-endian single-precision floating point number from a `Read`:

    use std::f32;
    use std::io::Cursor;

    use byteorder::{BigEndian, ReadBytesExt};

    let mut rdr = Cursor::new(vec![
        0x40, 0x49, 0x0f, 0xdb,
    ]);
    assert_eq!(f32::consts::PI, rdr.read_f32::<BigEndian>().unwrap());

### `fn read_f64<T: ByteOrder>(&mut self) -> Result<f64>`

Reads a IEEE754 double-precision (8 bytes) floating point number from the underlying reader.

# Errors

This method returns the same errors as `Read::read_exact`.

# Examples

Read a big-endian double-precision floating point number from a `Read`:

    use std::f64;
    use std::io::Cursor;

    use byteorder::{BigEndian, ReadBytesExt};

    let mut rdr = Cursor::new(vec![
        0x40, 0x09, 0x21, 0xfb, 0x54, 0x44, 0x2d, 0x18,
    ]);
    assert_eq!(f64::consts::PI, rdr.read_f64::<BigEndian>().unwrap());

### `fn read_u16_into<T: ByteOrder>(&mut self, dst: &mut [u16]) -> Result<()>`

Reads a sequence of unsigned 16 bit integers from the underlying reader.

The given buffer is either filled completely or an error is returned. If an error is returned, the contents of `dst` are unspecified.

# Errors

This method returns the same errors as `Read::read_exact`.

# Examples

Read a sequence of unsigned 16 bit big-endian integers from a `Read`:

    use std::io::Cursor;
    use byteorder::{BigEndian, ReadBytesExt};

    let mut rdr = Cursor::new(vec![2, 5, 3, 0]);
    let mut dst = [0; 2];
    rdr.read_u16_into::<BigEndian>(&mut dst).unwrap();
    assert_eq!([517, 768], dst);

### `fn read_u32_into<T: ByteOrder>(&mut self, dst: &mut [u32]) -> Result<()>`

Reads a sequence of unsigned 32 bit integers from the underlying reader.

The given buffer is either filled completely or an error is returned. If an error is returned, the contents of `dst` are unspecified.

# Errors

This method returns the same errors as `Read::read_exact`.

# Examples

Read a sequence of unsigned 32 bit big-endian integers from a `Read`:

    use std::io::Cursor;
    use byteorder::{BigEndian, ReadBytesExt};

    let mut rdr = Cursor::new(vec![0, 0, 2, 5, 0, 0, 3, 0]);
    let mut dst = [0; 2];
    rdr.read_u32_into::<BigEndian>(&mut dst).unwrap();
    assert_eq!([517, 768], dst);

### `fn read_u64_into<T: ByteOrder>(&mut self, dst: &mut [u64]) -> Result<()>`

Reads a sequence of unsigned 64 bit integers from the underlying reader.

The given buffer is either filled completely or an error is returned. If an error is returned, the contents of `dst` are unspecified.

# Errors

This method returns the same errors as `Read::read_exact`.

# Examples

Read a sequence of unsigned 64 bit big-endian integers from a `Read`:

    use std::io::Cursor;
    use byteorder::{BigEndian, ReadBytesExt};

    let mut rdr = Cursor::new(vec![
        0, 0, 0, 0, 0, 0, 2, 5,
        0, 0, 0, 0, 0, 0, 3, 0,
    ]);
    let mut dst = [0; 2];
    rdr.read_u64_into::<BigEndian>(&mut dst).unwrap();
    assert_eq!([517, 768], dst);

### `fn read_i16_into<T: ByteOrder>(&mut self, dst: &mut [i16]) -> Result<()>`

Reads a sequence of signed 16 bit integers from the underlying reader.

The given buffer is either filled completely or an error is returned. If an error is returned, the contents of `dst` are unspecified.

# Errors

This method returns the same errors as `Read::read_exact`.

# Examples

Read a sequence of signed 16 bit big-endian integers from a `Read`:

    use std::io::Cursor;
    use byteorder::{BigEndian, ReadBytesExt};

    let mut rdr = Cursor::new(vec![2, 5, 3, 0]);
    let mut dst = [0; 2];
    rdr.read_i16_into::<BigEndian>(&mut dst).unwrap();
    assert_eq!([517, 768], dst);

### `fn read_i32_into<T: ByteOrder>(&mut self, dst: &mut [i32]) -> Result<()>`

Reads a sequence of signed 32 bit integers from the underlying reader.

The given buffer is either filled completely or an error is returned. If an error is returned, the contents of `dst` are unspecified.

# Errors

This method returns the same errors as `Read::read_exact`.

# Examples

Read a sequence of signed 32 bit big-endian integers from a `Read`:

    use std::io::Cursor;
    use byteorder::{BigEndian, ReadBytesExt};

    let mut rdr = Cursor::new(vec![0, 0, 2, 5, 0, 0, 3, 0]);
    let mut dst = [0; 2];
    rdr.read_i32_into::<BigEndian>(&mut dst).unwrap();
    assert_eq!([517, 768], dst);

### `fn read_i64_into<T: ByteOrder>(&mut self, dst: &mut [i64]) -> Result<()>`

Reads a sequence of signed 64 bit integers from the underlying reader.

The given buffer is either filled completely or an error is returned. If an error is returned, the contents of `dst` are unspecified.

# Errors

This method returns the same errors as `Read::read_exact`.

# Examples

Read a sequence of signed 64 bit big-endian integers from a `Read`:

    use std::io::Cursor;
    use byteorder::{BigEndian, ReadBytesExt};

    let mut rdr = Cursor::new(vec![
        0, 0, 0, 0, 0, 0, 2, 5,
        0, 0, 0, 0, 0, 0, 3, 0,
    ]);
    let mut dst = [0; 2];
    rdr.read_i64_into::<BigEndian>(&mut dst).unwrap();
    assert_eq!([517, 768], dst);

### `unsafe fn read_f32_into_unchecked<T: ByteOrder>(
&mut self,
dst: &mut [f32]
) -> Result<()>`

Reads a sequence of IEEE754 single-precision (4 bytes) floating point numbers from the underlying reader.

The given buffer is either filled completely or an error is returned. If an error is returned, the contents of `dst` are unspecified.

# Safety

This method is unsafe because there are no guarantees made about the floating point values. In particular, this method does not check for signaling NaNs, which may result in undefined behavior.

# Errors

This method returns the same errors as `Read::read_exact`.

# Examples

Read a sequence of big-endian single-precision floating point number from a `Read`:

    use std::f32;
    use std::io::Cursor;

    use byteorder::{BigEndian, ReadBytesExt};

    let mut rdr = Cursor::new(vec![
        0x40, 0x49, 0x0f, 0xdb,
        0x3f, 0x80, 0x00, 0x00,
    ]);
    let mut dst = [0.0; 2];
    unsafe {
        rdr.read_f32_into_unchecked::<BigEndian>(&mut dst).unwrap();
    }
    assert_eq!([f32::consts::PI, 1.0], dst);

### `unsafe fn read_f64_into_unchecked<T: ByteOrder>(
&mut self,
dst: &mut [f64]
) -> Result<()>`

Reads a sequence of IEEE754 double-precision (8 bytes) floating point numbers from the underlying reader.

The given buffer is either filled completely or an error is returned. If an error is returned, the contents of `dst` are unspecified.

# Safety

This method is unsafe because there are no guarantees made about the floating point values. In particular, this method does not check for signaling NaNs, which may result in undefined behavior.

# Errors

This method returns the same errors as `Read::read_exact`.

# Examples

Read a sequence of big-endian single-precision floating point number from a `Read`:

    use std::f64;
    use std::io::Cursor;

    use byteorder::{BigEndian, ReadBytesExt};

    let mut rdr = Cursor::new(vec![
        0x40, 0x09, 0x21, 0xfb, 0x54, 0x44, 0x2d, 0x18,
        0x3f, 0xF0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    ]);
    let mut dst = [0.0; 2];
    unsafe {
        rdr.read_f64_into_unchecked::<BigEndian>(&mut dst).unwrap();
    }
    assert_eq!([f64::consts::PI, 1.0], dst);

## Implementors

- `impl<R: Read + ?Sized> ReadBytesExt for R`

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