# Struct base64::write::EncoderStringWriter

source · [−]

    pub struct EncoderStringWriter<S: StrConsumer> { /* private fields */ }

Expand description

A `Write` implementation that base64-encodes data using the provided config and accumulates the resulting base64 in memory, which is then exposed as a String via `into_inner()`.

## Examples

Buffer base64 in a new String:

    use std::io::Write;

    let mut enc = base64::write::EncoderStringWriter::new(base64::STANDARD);

    enc.write_all(b"asdf").unwrap();

    // get the resulting String
    let b64_string = enc.into_inner();

    assert_eq!("YXNkZg==", &b64_string);

Or, append to an existing String:

    use std::io::Write;

    let mut buf = String::from("base64: ");

    let mut enc = base64::write::EncoderStringWriter::from(&mut buf, base64::STANDARD);

    enc.write_all(b"asdf").unwrap();

    // release the &mut reference on buf
    let _ = enc.into_inner();

    assert_eq!("base64: YXNkZg==", &buf);

## Panics

Calling `write()` (or related methods) or `finish()` after `finish()` has completed without error is invalid and will panic.

## Performance

Because it has to validate that the base64 is UTF-8, it is about 80% as fast as writing plain bytes to a `io::Write`.

## Implementations

source

### impl<S: StrConsumer> EncoderStringWriter<S>

source

#### pub fn from(str_consumer: S, config: Config) -> Self

Create a EncoderStringWriter that will append to the provided `StrConsumer`.

source

#### pub fn into_inner(self) -> S

Encode all remaining buffered data, including any trailing incomplete input triples and associated padding.

Once this succeeds, no further writes or calls to this method are allowed.

Returns the base64-encoded form of the accumulated written data.

source

### impl EncoderStringWriter<String>

source

#### pub fn new(config: Config) -> Self

Create a EncoderStringWriter that will encode into a new String with the provided config.

## Trait Implementations

source

### impl<S: StrConsumer> Write for EncoderStringWriter<S>

source

#### fn write(&mut self, buf: &[u8]) -> Result<usize>

Write a buffer into this writer, returning how many bytes were written. Read more

source

#### fn flush(&mut self) -> Result<()>

Flush this output stream, ensuring that all intermediately buffered contents reach their destination. Read more

1.36.0 · source

#### fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> Result<usize, Error>

Like `write`, except that it writes from a slice of buffers. Read more

source

#### fn is_write_vectored(&self) -> bool

🔬 This is a nightly-only experimental API. (`can_vector`)

Determines if this `Write`r has an efficient `write_vectored` implementation. Read more

1.0.0 · source

#### fn write_all(&mut self, buf: &[u8]) -> Result<(), Error>

Attempts to write an entire buffer into this writer. Read more

source

#### fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> Result<(), Error>

🔬 This is a nightly-only experimental API. (`write_all_vectored`)

Attempts to write multiple buffers into this writer. Read more

1.0.0 · source

#### fn write_fmt(&mut self, fmt: Arguments<'_>) -> Result<(), Error>

Writes a formatted string into this writer, returning any error encountered. Read more

1.0.0 · source

#### fn by_ref(&mut self) -> &mut Self

Creates a “by reference” adapter for this instance of `Write`. Read more

## Auto Trait Implementations

### impl<S> RefUnwindSafe for EncoderStringWriter<S> where
S: RefUnwindSafe,

### impl<S> Send for EncoderStringWriter<S> where
S: Send,

### impl<S> Sync for EncoderStringWriter<S> where
S: Sync,

### impl<S> Unpin for EncoderStringWriter<S> where
S: Unpin,

### impl<S> UnwindSafe for EncoderStringWriter<S> where
S: UnwindSafe,

## Blanket Implementations

source

### impl<T> Any for T where
T: 'static + ?Sized,

source

#### fn type_id(&self) -> TypeId

Gets the `TypeId` of `self`. Read more

source

### impl<T> Borrow<T> for T where
T: ?Sized,

const: unstable · source

#### fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more

source

### impl<T> BorrowMut<T> for T where
T: ?Sized,

const: unstable · source

#### fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more

source

### impl<T> From<T> for T

const: unstable · source

#### fn from(t: T) -> T

Returns the argument unchanged.

source

### impl<T, U> Into<U> for T where
U: From<T>,

const: unstable · source

#### fn into(self) -> U

Calls `U::from(self)`.

That is, this conversion is whatever the implementation of `From<T> for U` chooses to do.

source

### impl<T, U> TryFrom<U> for T where
U: Into<T>,

#### type Error = Infallible

The type returned in the event of a conversion error.

const: unstable · source

#### fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.

source

### impl<T, U> TryInto<U> for T where
U: TryFrom<T>,

#### type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.

const: unstable · source

#### fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.