Macro log 

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

Impl filler: Generates an implementation that simply logs the parameters and returns ().

Syntax

#[portrait::fill(portrait::log($logger:path))]

You can also specify leading parameters to the macro call:

#[portrait::fill(portrait::log($logger:path, $($args:expr),*))]

• $logger is the path to the macro for logging, e.g. log::info or [println!].
• $args are the arguments passed to the macro before the format template, e.g. the log level in log::log or the writer in writeln!.

Associated constants are not supported. Associated types are always () (we assume to be the return likely type of $logger).

Currently, this macro does not properly support #[cfg] on arguments yet.

Example

// Imports required for calling the `write!` macro
use std::fmt::{self, Write};

#[portrait::make]
trait Foo {
    type Bar;
    fn qux(&mut self, i: i64) -> Self::Bar;
}

#[derive(Default)]
struct Receiver {
    buffer: String,
}

#[portrait::fill(portrait::log(
    write -> fmt::Result,
    &mut self.buffer,
))]
impl Foo for Receiver {}

let mut recv = Receiver::default();
recv.qux(3);
assert_eq!(recv.buffer.as_str(), "qux(3)");