Macro call

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

Call a function or primitive defined by a text expression with arbitrary parameters. This currently works by parsing and evaluating the string in R, but will probably acquire some shortcuts for simple expressions, for example by caching symbols and constant values.

    assert_eq!(call!("`+`", 1, 2), r!(3));
    assert_eq!(call!("list", 1, 2), r!([r!(1), r!(2)]));