# base64::write::EncoderStringWriter - Rust
API documentation for the Rust `EncoderStringWriter` struct in crate `base64`.
Keywords: rust, rustlang, rust-lang, EncoderStringWriter

# [−] [src] Struct base64::write::EncoderStringWriter

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

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

### `impl<S: StrConsumer> EncoderStringWriter<S>` [src]

#### `pub fn from(str_consumer: S, config: Config) -> Self` [src]

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

#### `pub fn into_inner(self) -> S` [src]

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.

### `impl EncoderStringWriter<String>` [src]

#### `pub fn new(config: Config) -> Self` [src]

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

## Trait Implementations

### `impl<S: StrConsumer> Write for EncoderStringWriter<S>` [src]

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

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

#### `fn flush(&mut self) -> Result<()>` [src]

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

#### `pub fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> Result<usize, Error>`1.36.0 [src]

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

#### `pub fn is_write_vectored(&self) -> bool` [src]

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

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

#### `pub fn write_all(&mut self, buf: &[u8]) -> Result<(), Error>`1.0.0 [src]

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

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

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

Attempts to write multiple buffers into this writer. Read more

#### `pub fn write_fmt(&mut self, fmt: Arguments<'_>) -> Result<(), Error>`1.0.0 [src]

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

#### `pub fn by_ref(&mut self) -> &mut Self` 1.0.0 [src]

Creates a "by reference" adaptor for this instance of `Write`. Read more

## Auto Trait Implementations

### `impl<S> RefUnwindSafe for EncoderStringWriter<S> where
S: RefUnwindSafe,` [src]

### `impl<S> Send for EncoderStringWriter<S> where
S: Send,` [src]

### `impl<S> Sync for EncoderStringWriter<S> where
S: Sync,` [src]

### `impl<S> Unpin for EncoderStringWriter<S> where
S: Unpin,` [src]

### `impl<S> UnwindSafe for EncoderStringWriter<S> where
S: UnwindSafe,` [src]

## Blanket Implementations

### `impl<T> Any for T where
T: 'static + ?Sized,` [src]

#### `pub fn type_id(&self) -> TypeId` [src]

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

### `impl<T> Borrow<T> for T where
T: ?Sized,` [src]

#### `pub fn borrow(&self) -> &T` [src]

Immutably borrows from an owned value. Read more

### `impl<T> BorrowMut<T> for T where
T: ?Sized,` [src]

#### `pub fn borrow_mut(&mut self) -> &mut T` [src]

Mutably borrows from an owned value. Read more

### `impl<T> From<T> for T` [src]

#### `pub fn from(t: T) -> T` [src]

Performs the conversion.

### `impl<T, U> Into<U> for T where
U: From<T>,` [src]

#### `pub fn into(self) -> U` [src]

Performs the conversion.

### `impl<T, U> TryFrom<U> for T where
U: Into<T>,` [src]

#### `type Error = Infallible`

The type returned in the event of a conversion error.

#### `pub fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>` [src]

Performs the conversion.

### `impl<T, U> TryInto<U> for T where
U: TryFrom<T>,` [src]

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

The type returned in the event of a conversion error.

#### `pub fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>` [src]

Performs the conversion.