Macro load_file::load_bytes

macro_rules! load_bytes {
    ($name:expr) => { ... };
}

Load a file as a reference to a byte array at run-time.

The file is located relative to the current source file, and the binary must be run with the crate root as the working directory.

The resulting value is a &'static [u8] with the contents of the file.

This macro can often be a drop-in replacement for include_bytes!, switching it to be a run-time rather than compile-time operation.

Each time the macro is reached, the file is read into memory in its entirety and the memory is leaked, keeping the memory valid for the remainder of the program execution.

Compatibility with include_bytes!

Apart from the semantic differences between include_bytes! and load_bytes! there are also some technical differences:

• With include_bytes!, the length of the array is statically known, and is included in the type: &'static [u8; N], vs &'static [u8] for load_bytes!
• include_bytes! can appear in static contexts in the source code, while load_bytes! can not. It is possible to use the lazy_static crate to work around this.

Example

#[macro_use]
extern crate load_file;

fn main() {
    let greeting: &[u8] = load_bytes!("greeting.txt");
    println!("{:?}", greeting);
}

Panics

To facilitate using load_bytes! as a drop-in replacement for include_bytes!, all error situations cause panics:

• File not found
• Read errors