Macro concatdoc 

concatdoc!() { /* proc-macro */ }

Unindent and call concat!.

Argument syntax is the same as for std::concat!.

Example

const HELP: &str = concatdoc! {"
    Usage: ", env!("CARGO_BIN_NAME"), " [options]

    Options:
        -h, --help
"};

print!("{}", HELP);

Usage: example [options]

Options:
    -h, --help