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use crate::io;
use crate::path::Path;
use crate::task::spawn_blocking;
use crate::utils::Context as _;

/// Writes a slice of bytes as the new contents of a file.

///

/// This function will create a file if it does not exist, and will entirely replace its contents

/// if it does.

///

/// This function is an async version of [`std::fs::write`].

///

/// [`std::fs::write`]: https://doc.rust-lang.org/std/fs/fn.write.html

///

/// # Errors

///

/// An error will be returned in the following situations:

///

/// * The file's parent directory does not exist.

/// * The current process lacks permissions to write to the file.

/// * Some other I/O error occurred.

///

/// # Examples

///

/// ```no_run

/// # fn main() -> std::io::Result<()> { async_std::task::block_on(async {

/// #

/// use async_std::fs;

///

/// fs::write("a.txt", b"Hello world!").await?;

/// #

/// # Ok(()) }) }

/// ```

pub async fn write<P: AsRef<Path>, C: AsRef<[u8]>>(path: P, contents: C) -> io::Result<()> {
    let path = path.as_ref().to_owned();
    let contents = contents.as_ref().to_owned();
    spawn_blocking(move || {
        std::fs::write(&path, contents)
            .context(|| format!("could not write to file `{}`", path.display()))
    })
    .await
}